Arch Linux, KDE, and LaserJet M477 MFP - tray 3 won't enable

I take it that the device is on the network and is using HPLIP.
Let's try a different approach. Give the outputs of

  avahi-browse -rt _ipp._tcp
  avahi-browse -rt _uscan._tcp
  driverlessavahi-browse -rt _ipp._tcp

Sure thing. driverlessavahi-browse doesn't appear to be installed on my machine (and no files with that name exist).

avahi-browse -rt_ipp._tcp:

+ wlan0 IPv6 HPM477 Internet Printer local
+ wlan0 IPv6 CUPS HP LaserJet M203-M206 @ cups-server Internet Printer local
+ wlan0 IPv6 CUPS-HP Color LaserJet MFP M477fnw @ cups-server Internet Printer local
+ wlan0 IPv6 HPM203 Internet Printer local
+ wlan0 IPv4 HPM477 Internet Printer local
+ wlan0 IPv4 CUPS HP LaserJet M203-M206 @ cups-server Internet Printer local
+ wlan0 IPv4 CUPS-HP Color LaserJet MFP M477fnw @ cups-server Internet Printer local
+ wlan0 IPv4 HPM203 Internet Printer local
= wlan0 IPv6 HPM477 Internet Printer local
   hostname = [HPM477.local]
   address = [192.168.1.40]
   port = [631]
   txt = ["mopria_certified=1.2" "mac=00:00:00:00:00:00" "usb_MDL=HP Color LaserJet MFP M477fnw" "usb_MFG=Hewlett-Packard" "TLS=1.2" "PaperMax=legal-A4" "kind=document,envelope,photo" "UUID=564e4238-4a37-3843-4d4b-ec8eb5bc0401" "Fax=T" "Scan=T" "Duplex=F" "Color=T" "note=" "adminurl=http://HPM477.local./hp/device/info_config_AirPrint.html?tab=Networking&menu=AirPrintStatus" "priority=10" "product=(HP Color LaserJet MFP M477fnw)" "ty=HP Color LaserJet MFP M477fnw" "URF=V1.4,CP99,W8,OB10,PQ3-4-5,ADOBERGB24,DEVRGB24,DEVW8,SRGB24,IS1,MT1-2-3-4-5-12,RS600" "rfo=ipp/faxout" "rp=ipp/print" "pdl=image/urf,application/pdf,application/postscript,application/vnd.hp-PCL,application/vnd.hp-PCLXL,application/PCLm,application/octet-stream,image/jpeg" "qtotal=1" "txtvers=1"]
= wlan0 IPv6 CUPS HP LaserJet M203-M206 @ cups-server Internet Printer local
   hostname = [cups-server.local]
   address = [fe80::40ac:c6ff:fe9a:4b5c]
   port = [631]
   txt = ["printer-type=0x809056" "Copies=T" "Duplex=T" "mopria-certified=1.3" "URF=V1.4,CP1,W8,PQ4,RS600,DM1,FN3" "TLS=1.2" "UUID=205ea72a-6cd0-3dee-5bc8-3cd61d0e5e88" "pdl=application/pdf,application/postscript,image/jpeg,image/png,image/pwg-raster,image/urf" "product=(LaserJet M203-M206)" "priority=0" "note=" "adminurl=https://cups-server.local.:631/printers/HP_LaserJet_M203dw" "ty=HP LaserJet Pro M203-M206 Postscript (recommended)" "rp=printers/HP_LaserJet_M203dw" "qtotal=1" "txtvers=1"]
= wlan0 IPv6 CUPS-HP Color LaserJet MFP M477fnw @ cups-server Internet Printer local
   hostname = [cups-server.local]
   address = [fe80::40ac:c6ff:fe9a:4b5c]
   port = [631]
   txt = ["printer-type=0x8090CE" "Collate=T" "Copies=T" "Color=T" "mopria-certified=1.3" "URF=V1.4,CP1,W8,PQ4,SRGB24,RS600,FN3" "TLS=1.2" "UUID=ab2c4ee3-1844-34e5-4c7f-e1746ca5d7ca" "pdl=application/pdf,application/postscript,image/jpeg,image/png,image/pwg-raster,image/urf" "product=(HP Color LaserJet MFP M477fdw)" "priority=0" "note=" "adminurl=https://cups-server.local.:631/printers/HP_Color_LaserJet_MFP_M477fnw" "ty=HP Color LaserJet Pro MFP M477 Postscript (recommended)" "rp=printers/HP_Color_LaserJet_MFP_M477fnw" "qtotal=1" "txtvers=1"]
= wlan0 IPv6 HPM203 Internet Printer local
   hostname = [HPM203.local]
   address = [192.168.1.41]
   port = [631]
   txt = ["mopria-certified=1.3" "mac=00:00:00:00:00:00" "usb_MDL=HP LaserJet M203-M206" "usb_MFG=HP" "TLS=1.2" "PaperMax=legal-A4" "kind=document,envelope,photo" "UUID=564e4235-4436-3330-3833-040e3c6796a8" "Fax=F" "Scan=F" "Duplex=T" "Color=F" "note=" "adminurl=http://HPM203.local./hp/device/info_config_AirPrint.html?tab=Networking&menu=AirPrintStatus" "priority=10" "product=(HP LaserJet M203-M206)" "ty=HP LaserJet M203-M206" "URF=V1.4,CP99,W8,OB10,PQ3-4-5,DM1,IS1,MT1-3-5,RS600" "rp=ipp/print" "pdl=image/urf,application/PCLm,application/octet-stream,application/pdf,application/postscript,application/vnd.hp-PCL,application/vnd.hp-PCLXL,image/jpeg" "qtotal=1" "txtvers=1"]
= wlan0 IPv4 HPM477 Internet Printer local
   hostname = [HPM477.local]
   address = [192.168.1.40]
   port = [631]
   txt = ["mopria_certified=1.2" "mac=00:00:00:00:00:00" "usb_MDL=HP Color LaserJet MFP M477fnw" "usb_MFG=Hewlett-Packard" "TLS=1.2" "PaperMax=legal-A4" "kind=document,envelope,photo" "UUID=564e4238-4a37-3843-4d4b-ec8eb5bc0401" "Fax=T" "Scan=T" "Duplex=F" "Color=T" "note=" "adminurl=http://HPM477.local./hp/device/info_config_AirPrint.html?tab=Networking&menu=AirPrintStatus" "priority=10" "product=(HP Color LaserJet MFP M477fnw)" "ty=HP Color LaserJet MFP M477fnw" "URF=V1.4,CP99,W8,OB10,PQ3-4-5,ADOBERGB24,DEVRGB24,DEVW8,SRGB24,IS1,MT1-2-3-4-5-12,RS600" "rfo=ipp/faxout" "rp=ipp/print" "pdl=image/urf,application/pdf,application/postscript,application/vnd.hp-PCL,application/vnd.hp-PCLXL,application/PCLm,application/octet-stream,image/jpeg" "qtotal=1" "txtvers=1"]
= wlan0 IPv4 CUPS HP LaserJet M203-M206 @ cups-server Internet Printer local
   hostname = [cups-server.local]
   address = [192.168.1.36]
   port = [631]
   txt = ["printer-type=0x809056" "Copies=T" "Duplex=T" "mopria-certified=1.3" "URF=V1.4,CP1,W8,PQ4,RS600,DM1,FN3" "TLS=1.2" "UUID=205ea72a-6cd0-3dee-5bc8-3cd61d0e5e88" "pdl=application/pdf,application/postscript,image/jpeg,image/png,image/pwg-raster,image/urf" "product=(LaserJet M203-M206)" "priority=0" "note=" "adminurl=https://cups-server.local.:631/printers/HP_LaserJet_M203dw" "ty=HP LaserJet Pro M203-M206 Postscript (recommended)" "rp=printers/HP_LaserJet_M203dw" "qtotal=1" "txtvers=1"]
= wlan0 IPv4 CUPS-HP Color LaserJet MFP M477fnw @ cups-server Internet Printer local
   hostname = [cups-server.local]
   address = [192.168.1.36]
   port = [631]
   txt = ["printer-type=0x8090CE" "Collate=T" "Copies=T" "Color=T" "mopria-certified=1.3" "URF=V1.4,CP1,W8,PQ4,SRGB24,RS600,FN3" "TLS=1.2" "UUID=ab2c4ee3-1844-34e5-4c7f-e1746ca5d7ca" "pdl=application/pdf,application/postscript,image/jpeg,image/png,image/pwg-raster,image/urf" "product=(HP Color LaserJet MFP M477fdw)" "priority=0" "note=" "adminurl=https://cups-server.local.:631/printers/HP_Color_LaserJet_MFP_M477fnw" "ty=HP Color LaserJet Pro MFP M477 Postscript (recommended)" "rp=printers/HP_Color_LaserJet_MFP_M477fnw" "qtotal=1" "txtvers=1"]
= wlan0 IPv4 HPM203 Internet Printer local
   hostname = [HPM203.local]
   address = [192.168.1.41]
   port = [631]
   txt = ["mopria-certified=1.3" "mac=00:00:00:00:00:00" "usb_MDL=HP LaserJet M203-M206" "usb_MFG=HP" "TLS=1.2" "PaperMax=legal-A4" "kind=document,envelope,photo" "UUID=564e4235-4436-3330-3833-040e3c6796a8" "Fax=F" "Scan=F" "Duplex=T" "Color=F" "note=" "adminurl=http://HPM203.local./hp/device/info_config_AirPrint.html?tab=Networking&menu=AirPrintStatus" "priority=10" "product=(HP LaserJet M203-M206)" "ty=HP LaserJet M203-M206" "URF=V1.4,CP99,W8,OB10,PQ3-4-5,DM1,IS1,MT1-3-5,RS600" "rp=ipp/print" "pdl=image/urf,application/PCLm,application/octet-stream,application/pdf,application/postscript,application/vnd.hp-PCL,application/vnd.hp-PCLXL,image/jpeg" "qtotal=1" "txtvers=1"]

avahi-browse -rt_uscan._tcp:

+ wlan0 IPv4 HPM477 _uscan._tcp local
+ wlan0 IPv6 HPM477 _uscan._tcp local
= wlan0 IPv4 HPM477 _uscan._tcp local
   hostname = [HPM477.local]
   address = [192.168.1.40]
   port = [8080]
   txt = ["note=" "duplex=T" "is=platen,adf" "cs=color,grayscale" "pdl=application/pdf,image/jpeg" "uuid=564e4238-4a37-3843-4d4b-ec8eb5bc0401" "rs=eSCL" "representation=http://HPM477.local/ipp/images/printer.png" "vers=2.5" "usb_MDL=HP Color LaserJet MFP M477fnw" "usb_MFG=Hewlett-Packard" "mdl=MFP M477fnw" "mfg=Hewlett Packard" "ty=HP Color LaserJet MFP M477fnw" "adminurl=http://HPM477.local." "txtvers=1"]
= wlan0 IPv6 HPM477 _uscan._tcp local
   hostname = [HPM477.local]
   address = [192.168.1.40]
   port = [8080]
   txt = ["note=" "duplex=T" "is=platen,adf" "cs=color,grayscale" "pdl=application/pdf,image/jpeg" "uuid=564e4238-4a37-3843-4d4b-ec8eb5bc0401" "rs=eSCL" "representation=http://HPM477.local/ipp/images/printer.png" "vers=2.5" "usb_MDL=HP Color LaserJet MFP M477fnw" "usb_MFG=Hewlett-Packard" "mdl=MFP M477fnw" "mfg=Hewlett Packard" "ty=HP Color LaserJet MFP M477fnw" "adminurl=http://HPM477.local." "txtvers=1"]

driverlessavahi-browse is a copy and paste error. The command is

  driverless

We can manage without it.

The M477 printer is at 192.168.1.40 with a hostname of HPM477.local.

Execute

  lpadmin -p M477 -v ipp://HPM477.local/ipp/print -E -m everywhere

Test with

  lp -d M477 /etc/nsswitch.conf

Obtain the output from the next command and record it here:

  lpoptions -p M477 -l

Does it give three input trays? Do all work?

I used a name other than "M477" and lpoptions worked

lpoptions -p M477 -l:

relevant line:
HPOption_Tray3/Tray 3: *False True

PageSize/Media Size: *Letter Legal Executive FanFoldGermanLegal 4x6 5x8 A4 A5 A6 B5 B6 Env4x6 Oficio 195x270mm 184x260mm 7.75x10.75 Postcard DoublePostcardRotated Env10 EnvMonarch EnvISOB5 EnvC5 EnvDL Custom.WIDTHxHEIGHT
Collate/Collate: True *False
InputSlot/Paper Feed: *Auto Tray1 Tray2 Tray3 ManualFeed
HPOption_Tray3/Tray 3: *False True
MediaType/Media Type: *Unspecified Plain HPEcoFFICIENT HPLaserJet90 HPColorLaserMatte105 HPPremiumChoiceMatte120 HPBrochureMatte150 HPCoverMatte200 HPMattePhoto200 HPPremiumPresentationGlossy120 HPBrochureGlossy150 HPTrifoldBrochureGlossy150 HPBrochureGlossy200 Light6074 Intermediate8595 MidWeight96110 Heavy111130 ExtraHeavy131175 Cardstock176220 HeavyGlossy111130 ExtraHeavyGlossy131175 CardGlossy176220 ColorLaserTransparency Labels Letterhead Envelope HeavyEnvelope Preprinted Prepunched Colored Bond Recycled Rough HeavyRough OpaqueFilm
HPPJLEconoMode2/EconoMode: on *off
HPEdgeControl/Edge Control: HPEdgeControlOff Light *Normal Max
HPGeneralHalftone/Halftone: *Smooth Detail
HPTextNeutralGrays/Text Neutral Grays: *Black ProcessBlack
HPGraphicsNeutralGrays/Graphics Neutral Grays: *Black ProcessBlack
HPPhotoNeutralGrays/Photo Neutral Grays: Black *ProcessBlack
HPPJLColorAsGray/Print Color as Gray: on *off
HPRGBEmulation/RGB Color: *DefaultSRGB PhotoSRGB Adobe VividSRGB HPRGBEmulationNone

Perhaps the issue should be marked as solved now?

No - the third tray shouldn't be disabled, but I can't figure out how to enable it on Linux. I didn't have to do anything in MacOS for the third paper tray to be available in the system print dialog.

I don't see any means of enabling the tray through the printer's firmware, so I'm unsure where to go from here.

That's what I was missing, thank you! Does running the lpoptions command permanently set the configuration, or do I need to edit one of the configs for the setting to persist between reboots?

Thanks Manfred Hampl, that solved my question.