I found a solution myself and I can confirm it myself. Well it's because of your age, now don't worry about your account . To get the link option without deleting and changing the age for the account, I will say to reinstall the game and then put the legal age for your country like I found countrys that needs you to be 18 to 13 so if you know the legal age for your country then you can put that and then you can get that game option , not the facebook (I can't confirm if you will get your saved game by clicking facebook) or the guest mode. Then you will get told if you want to change your somehow saved child account or new account so obivously we need legal age saved account so click the saved child account and then you will turn it into the legal age and get to link! , The thing is I spent alot of time thinking how to do this and I was able to do it so try it!
I lost my account cuz of this
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