how to connect an epson et-2710 to iPhone 12 Pro Max

Hi,

As indicated by Miss Smartie Partie, this does not appear to be an AirPrint-enabled model.

However, it should be possible to use an app from the printer manufacturer:

https://apps.apple.com/us/app/epson-iprint/id326876192

(an ET-2710 Series is mentioned under supported models in https://support.epson.net/appinfo/iprint/en/).

The printer has to be an AirPrint printer to print from an iPhone. If the printer isn't AirPrint compatible you can't use it.

https://support.apple.com/en-us/HT201387

I don't see your printer on the list of compatible AirPrint printers, though: https://support.apple.com/en-us/HT201311