Pls follow the steps as below: 

-Connect your IOS device and your projector to the same Wi-Fi network. 

-Open the airplay of your IOS device, tap the Airplay 

-Tap the name of the device you want to stream contents. 

Note: When you choose the Airplay device, audio, photo and videos from your IOS device will play on your projector. 

If you turn on mirroring, you will see entire IOS screen the projector screen. To use Airplay, you need one of these devices: iPhone5/iPhone6 series/iPhone7 series for Airplay Mirroring. iPad2 or above version for Airplay Mirroring. iPod touch 5th generation or above for Airplay Mirroring.