Firstly you need an AirPrint supported wireless printer or a printer attached to a Mac and a conduit tool such as Printopia installed on it and all on the same WiFi network as the iOS device.
The printopia Mac App acts as a wireless printer server and when set up on the Mac allows any printer to appear as an Airprint supported printer on nearby iOS and iPadOS devices.
Now open the pdf to view . In the top menu bar clip on the square with up arrow icon scroll down to print and tap on it .
Now in the print window if no printer is immediately found then tap on select printer and scan for nearby WiFi enabled or Pintopia printers on your network
When and if found select the printer you want
Return to previous window select any other options quantity etc..
In the top right hand corner hit print and the job will be parsed to the printer .