How to obtain the username of an old, unused account

[Squid]

I had an account that I used for Trello many years ago while at a university. It has a username that I'd like to use for my current account, but I have no way of accessing it anymore as it seemingly was created with a school email that no longer exists.

If I am able to provide verification of ownership somehow, would I be able to delete that account or at least change its username to free it up for me to use instead?

[Gaurav Kataria]

Please check this page: Recovering your Trello account