I can't add my phone number to my apple id
I'm trying to add my phone number, which I have always had and two-factor authentication is tied to it, but the site writes that this phone number is already used in another account. Although I don't have any other accounts, I'm trying to forget my password to log into this account, which apple supposedly says is already in use, but when I try to forget my password it says Apple ID is invalid or unsupported.
iPhone 14 Pro, iOS 17