Call of Duty Mobile Login with Apple Id

After downloading to Call of duty I bypassed creating and cod account and just logged in with my Apple ID. I now have a Ps 5 and want to link everything. When I go in to create a Cod account it ask for my username. I put the username i created using the Apple ID login. It says that it is already in use. How do I link my Apple ID login to COd login I’m not seeing an option to do that.