I have provided a lot of proofs but I ignored them and didn’t say at the beginning that only Bitcoin signatures can be provided nor said that only these exchanges will have Bitcoin signatures.
You provided a lot of things I didn't ask for and that are of no use. You repeatedly ignored that I was telling you that a Bitcoin signed message was the only thing that would be acceptable when someone claims an account is theirs even when they don't have the email account associated with that account.