Can't log in to Google play store?

[Tony Starks]

On my sons galaxy tab his closed school email address is stopping us from accessing the play store.

When we go through the process to add his home email it won't let us because it says the account already exists on his device.






Any ideas?

And that's before we even try to link his sisters tablet played minecraft to his switch minecraft

[Corso Marche]

You've selected the "Use Another Account" option shown in your photo, right?
What happens after doing that and following the prompts?