I have Starz with my cable provider. Apple TV does not have the Starz app. No worries you say. Just use AirPlay, sign in from the website and watch on your TV. Sounds like a great idea. Except it doesn't play. I hit play and screen is frozen. When I

The developer can opt to block AirPlay

I Had this same problem. Very easy to fix.

Have your Apple TV on and ready.

OOpen the starz app on your phone or iPad and begin playing your starz program.

Once movie or show is playing swipe up to open the AirPlay options.

Choose the AppleTV to AirPlay as usual but DO NOT select mirroring.

CLick done. Swipe down to hide the toolbar and you should be good to go.

ANother tip. In many cases people have trouble with airplay when connecting to a 5 GHz Network.

If you are connected to a 5 GHz network try the 2 GHz network instead or even better plug it in via ethernet.

Worked like magic for me. Hope it does for you.

From Starz FAQ.

Is there AirPlay support on STARZ Play? No, we do not currently offer any kind of support for AirPlay, but weareconstantly looking for ways to grow and expand our service, so it may bean option in the future.

TThis worked. Thanks!

I found that mirroring works fine with Firefox but does work with Safari.