The list in About AirPrint - Apple Support confirms that the Epson WF-2750 is a printer supporting the AirPrint technology (as you already know), so it should be possible to print from an iPad (without the need for an extra app from the printer manufacturer).
Use AirPrint to print from your iPhone, iPad or iPod touch – Apple Support
I assume that the printer, the computer, the Android phones, and the iPads are connected to one Wi-Fi router. The printer and the iPads must use the same network. Depending on the router/settings, one may have to check 2.4 and 5 GHz network names, etc.
One may also want to power cycle all devices according to the following procedure: Power off the router, the printer, the computer, and all mobile phones and iPads. Wait two to three minutes. Power on the router. Wait another two to three minutes. Power on the printer. Wait a minute or two. Power on the computer. Finally, power on all mobile phones and iPads.