How to forward ports to the printer?

Question

HP

There is an HP Deskjet Ink Advantage 2540. It has a muzzle, but there is an IPP, I can get through to the muzzle, but I can’t reach the IPP.
Here are the redirect rules settings:

What could be the problem?
Thanks in advance!

Answer 1

So skip the server ip and find out what ports are open there and try to forward try to forward 631 tcp

Answer 2

You apparently have TCP or UDP, but you need both.
Also, Zyxel itself may have a print server and the port may already be busy.
Try disabling the print server.

Answer 3

Print port 9100. Try it.