On your Mac

1. Open the Finder window, then select AirDrop > Everyone

2. Make sure Wi-Fi and Bluetooth are turned on 

On your iPhone or iPad

1. Go to Settings> General > AirDrop > then select Everyone for 10 minutes (  If you want to AirDrop after 10 minutes, you have to repeat these steps )

2. Make sure Wi-Fi and Bluetooth are turned on.
3. Make sure your devices are closer together.
4. Check your device’s battery power.

AirDrop uses a combination of Bluetooth and Wi-Fi to work, both of which use a lot of energy. If your device's battery is too low, AirDrop can stop working. If your battery is less than 20%, try charging it and then try your AirDrop transfer again. If you can't access a power source, check your device's battery settings to see if Low Power Mode is on. If it is, temporarily turn off the feature and attempt the transfer again.

5. If you are still unable to AirDrop reboot your iOS Device and try