Hi,
The ET-2400 does not appear to be a model for Apple's AirPrint technology, so you would need an app from the printer manufacturer. The ET-2400 is listed as supported for the Epson Smart Panel.
https://support.epson.net/appinfo/smartpanel/guide/en/
https://apps.apple.com/us/app/epson-smart-panel/id1477796092?platform=ipad
Are you using this app on the iPad?
Generally speaking, if there is a problem with device discovery, and if all Wi-Fi settings are OK, it may be worth testing a power-cycle procedure: Power off the Wi-Fi router, the printer, the iPad, and all other computers/devices. Wait two to three minutes. Power on the router. Wait two to three minutes. Power on the printer. Wait a minute or two. Power on the iPad. Finally, power on all other computers/devices.