Unable to authenticate account due to old email

Trying to login to a new pc and the authentication wants to send the code to an old email that no longer exists and has been deleted. The email used to login to my account doesn’t seem to be an option to receive this code which does not make sense to me. I login with my email and password then it prompts for an authentication code to that old email and I’m not getting another option. Help!!! Microsoft also doesn’t seem to have a support line which is odd for how large the company is.