If you want to log in with your email and password or you get the error message "illegitimate request", you have to convert your account to a mobile account.
First tap on Login data on the main screen and after tap on the option " Separate the game from Google/Facebook"
First tap on Login data on the main screen and after tap on the option " Separate the game from Google/Facebook"
After tapping on "ok" you will be able to register a email and password.
Once you have entered your new login data, tap on send registration. An activation email will be sent to the entered email so that you can play on multiple devices.