My experience with my HP multi-function printer (different model from yours).
System Preferences -> Print & Scan
Select my printer from the list of printers.
Click on the "Scan" tab
Click "Open Scanner..."
I do not know if this is how your HP printer and drivers will work. I is just how my HP multi-function printer works.
NOTE: The FAX component of my multi-function printer had to be configured separately from the printer/scanner setup. The FAX is setup as another printer, as in your print to the FAX, so it looks like another printer choice when configuring the printers. Again, you mileage may vary, as you have different HP printer from mine.