My airplay is not appearing on my iphone

I just bought an appletv and have set it up. I am trying to mirror my iphone screen to my tv, but the airplay icon is not appearing. My phone is connected to the same wifi as the appletv. The youtube is working fine on the appletv. I have airplay "on" on the appletv. Why isn't my airplay icon appearing on my phone? I have airdrop switched to "everyone". How can I fix this? (I have tried this on an iphone 5s and iphone 5)