Question: where can i find the wps pin on my hp officejet pro 7740?
Answer: To begin with, go to the Settings icon on your HP Officejet pro 7740 Printer Touch panel.
Then, Go to Network Settings. ... 
Here you can see all the information about your HP Officejet pro 7740 Printer Network settings.
Also, you can see your printer's WPS PIN here.