I'm not old enough when i am to access online

@shaunthegamer7 Is there any chance that either your Xbox or Origin account are underage? Can you play other EA/non-EA games? I'd guess that if only your Xbox account was flagged as underage then you would have encountered this with many games. 

Your posting account isn't linked to an Xbox account so I can't check on it from here. 

Perhaps aging up the account using the steps here will help: https://help.ea.com/en-in/help/account/aging-up-an-origin-account-to-an-adult-account/

Thanks.