Making a Forgejo User Admin via the database
You can make a forgejo user admin by connecting to the Database, e.g.
psql --user=forgejo
\c forgejo # select db named forgejo
Show user list
SELECT * FROM public."user";
Find the user you want to make admin, take notes of the id, next make them admin. Don't forget the "WHERE" clause!!!!
UPDATE public."user" SET is_admin = true WHERE id = 8;
Warning!
This is not an official way, use at your own risk. It worked for me as a workaround when I wasn't able to do it via the forgejo-cli, but it is very risky as it bypasses all internal logic of forgejo and might not work in the future or cause other problems.