I don't have your exact printer, but I've attached a couple of screenshots that may help you locate the controls.
First, after you select Print, if your selected printer dialog has a 'down' button next to the printer name, click on that to reveal additional print options. For most Mac apps, then click the Layout button to display additional options.
(If you're in Safari, when you select 'Print', the button you want for additional options is probably labeled 'Safari' rather than 'Layout')
On the LaserJet, the option is called Paper Feed, as shown below.
On my Canon inkjet, it's listed under Quality & Media, Paper Source...
Once you've located it and selected the desired option(s), be sure to use the Presets, Save As option to save your new settings as a Preset for future use. You'll have the option to save for ALL printers or only the selected printer. Because my printers are quite different, I always save for ONLY the selected printer, to avoid potential problems.
As you can see, I try to make my presets quite descriptive, because I have a lot of very specific settings for print jobs I use just once or twice a year, but year after year.
Message was edited by: kostby
Please clarify your intention by a manual tray, the HP Officejet J6480 only have a single input tray as you may find by its speciifcation:
Ensure your cards are supported by the hardware, which supports up to 200 g/m2 cards.