Technical How to recover an account that has unaccessible email?

[Shinimasen]

I have 1 webs backup from 2021, last time I logged the character that is the guild leader was 2 years ago.
I do know the username and the password and a few screenshots with my druild name that appears now as C_numbers.

But that Two-factory authentication sends an email to something long forgotten and probably mail itself not existing anymore.

So how do I proceed from here? (Or how do I change the email to a working one?)

[Repost]

Email your request to [email protected]