If you are getting a message in AltaMail Go about contact access, then you need to check your device access settings.

Open the Apple iPad/iPhone "Settings" app > Privacy > Contacts > AltaMail Go. Check that AltaMail Go is set to "on".

Also open the Settings app -> General -> Restrictions -> Contacts (near bottom). Check that AltaMail Go is set to "on".

Also tap into the Settings app > Scroll near the bottom and click on our AltaMail Go. Turn on "Contacts".