Playing iTunes on my PC thru speakers connected to Yamaha RX-V638 AV receiver via my home network

I have my music and video libraries stored on my PC (Windows 10). I have a Yamaha RX-V638 Av receiver which supports Airplay. I am trying to get music played on the PC with iTunes, to play on the speakers connected to the receiver over my home network. I select Airplay as the source input of the receiver, then I attemt to click the Airplay icon on the iTumes to select the receiver. Nothing happens when I click the Airplay icon. If I start playing a track, the icon disappears. Can someone give me an idea of what sized hammer is needed to solve this issue.