We're working on implementing a more convenient way to change usernames.
Right now to change your username you need to:
Create a new UG account using Continue with email option.
Contact us at [email protected] with the old and new accounts' usernames and emails.
We'll transfer your Pro subscription and Favorites to your new account and delete the old one.
Note: Playlists and shots can't be transferred to the new account.
[iOS] How to change my password or email