Canon EOS-1D X Mark III Advanced User's Manual page 537

Sending Images to a Smartphone from the Camera
You can use the camera to send images to a smartphone paired via Bluetooth (Android
devices only) or connected via Wi-Fi.
1.
Switch to playback.
2.
Press the <
3.
Select [
4.
Select sending options and send the images.
> button.
Send images to smartphone].
If you perform this step while connected via Bluetooth, a message is
displayed, and the connection switches to a Wi-Fi connection.
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