How do I connect my iPhone SE to my ho printer using wifi?

I installed a new wifi router. I can not get my iPhone SE to connect to my HP6968 office jet all-in-one printer. Both my phone and the printer are signed In to the wifi router but I can not get my phone to connect to the printer when i want to print something. If I select to print, it tells me it is not connected. I have restarted everything in the order my hp instructions tell me too but nothing works. I installed the hp printer App on my phone but I can’t get it to work either. With my old wifi router, I just connect the printer with the wifi password, told my print job to print, it gave me the option to select the printer and would print. Now if I select the printer, it says it’s not connected! Any ideas????