Unlinkage. 22/9/19

My TOT account is linked to an old hoyolab email that isn’t secure but because of the way they set it up, I can’t change it and link it to my secure hoyolab account. I’m at risk at losing my account because I can’t change it to a more secure email and it’s ridiculous that such a simple function isn’t included. Please add a way to unlink and change it because I don’t want to loose my account. I have nothing against the game itself, but the fact a simple safety-help measure isn’t implemented is ridiculous.