I suspect that I've had more experience with HP's non-support than you have.
And a look at the specs says that the duplexing on that machine is
manual. You've got to flip over the pages yourself. I'd really suggest that you read the manual and that you contact HP support to get further info. Good luck finding someone at HP support who will answer the phone in under a half hour to 45 minutes. And when you get an actual human on the phone, good luck finding one who knows that HP supports Macs. And should you by some miracle locate a customer support agent who not only picks up the phone but knows that HP supports Macs, good luck finding one who will tell you more than what I just did: read the manual.
This is the voice of bitter experience talking. But, hey, you'll learn.
And, no, just because the driver option is there doesn't mean that it's possible. The list of 'features' on HP devices which don't work properly or at all on Macs is lengthy. (Hint: try to scan something on a Mac running Leopard using a HP MFD or scanner built before 2007. Go ahead. Try. I'll wait. I won't hold my breath while waiting, though... There's a reason why my old HP MFD is currently connected to a machine running XP.) But, again, you'll learn.