Yes you can. I tried using a usb c to hdmi female adapter, but the screen flickers continuously. So here is the solution:
You need to connect the rog phone 2 to a usb-c to hdmi adapter, then connect it to a hdmi splitter (find one which specifically removes hdcp) via a hdmi cable. Now the 2 outputs of the splitter can be used to connect to your tv or elgato. This is working fine for me.