How do I create super users?

How can I create a super user?

We cannot provide users with full superuser credentials because that would remove a layer of security in our cloud offering: PostgreSQL superusers can access files on the host machine and execute arbitrary code not present in PostgreSQL. We are, however, trying to provide a superuser-like experience for the primary registered user.

What features do you want to use, that a superuser can access but your current user can’t?

I was trying to copy from a local CSV file into the db
psycopg2.errors.InsufficientPrivilege: must be superuser or a member of the pg_read_server_files role to COPY from a file

In that case, please look at my comment in How to grant pg_read_server_files role?, as it seems like your attempt is to COPY files from the PostgreSQL server instead of your local drive.