How to add MAC address to MAC address filter

Hello. Does anyone know how to help me connect my HP printer to Xfinity internet? The HP printer error message says that I either need to disable MAC address filtering (sounds like a security risk) or add the MAC adddress of my printer to the Xfinity router. How do I do this? I know the MAC address, but don't know how to add it.

I'd also like to express how frustrating it is to get a runaround from the customer support phone line, only to be redirected to their AI bot, which is another 10 minute runaround with no answers or help available for my question. Then another 10 minutes trying to find a solution on Google and 5 more minutes to post the question on this forum.  This forum is my best hope for finding a solution!