Originally Posted by
Puri
You PC is probably connected via etheret cable to the router, but you need to connect it via wifi to the router (just like your xbox). Usually it is not recommended if there is a ethernet connection available, but for Miracast it's a requirement.
You can just buy a wifi usb dongle (and connect it to your router just like your phone or xbox, and unplug your ethernet cable). Unless you buy some old wifi dongle they should support Miracast, you can just google your selected product to see if it's compatible.
A quick search seems to recommend "TP-Link Archer T3U AC1300" as cheap reliable Miracast dongle.