How to use airplay

have you read

Use AirPlay to stream video or mirror the screen of your iPhone, iPad, or iPod touch - Apple Support

To airplay pics or videos try the following.

• make sure your iPhone is connected Wi-Fi or Ethernet which is on the same network as the Apple TV
• open photos,
• tap library
• tap video or photos
• select ones you want to airplay
• then scroll up from bottom of iPhone, you should see airdrop, and airplay options
• tap airplay
• select name of Apple TV to play