Canon EOS-1D X Mark III Advanced User's Manual page 640

2.
Configure the [Login name] or [Password].
Select [Login name] and [Password] to access the virtual keyboard
( ) and enter the login name and password.
Select [OK] to return to the screen in step 1. Follow steps 1–2 for each
account to be used.
3.
Select [OK].
4.
Select [OK].
640