Question about Epson Eh-Tw5650

This is probably not possible directly. So either copy the Blueray disc to the computer first and play it from there. Or attach an external Blueray drive to the computer, play it that way and, as before, mirror the screen on the beamer.

It needs a WLAN network (the one already in place), then the Epson iprojection app must be installed on the computer or smartphone. When the projector is started, a screen appears, "Connection instructions" at the bottom right. The beamer is connected to the existing WLAN network and the screen content of the computer or smartphone is mirrored by the beamer.

Yes, this works perfectly. The beamer is WLAN-capable without additional hardware.