Root account disappeared

I’m using Gitlab CE. When I tried to login as root I could not get in.
When I tried resetting it using the procedure:
the root account could not be found but other accounts still exist:
root@8a709478cfdc:/opt/gitlab# gitlab-rails console -e production

GitLab: 11.7.6 (bcd4e1f)
GitLab Shell: 8.4.4
postgresql: 9.6.11

Loading production environment (Rails
irb(main):001:0> user = User.where(id: 1).first
=> nil
irb(main):002:0> user = User.where(id: 2).first
=> #<User id:2 @cees>

Since I haven’t used the root account in quite restoring a backup is not a good option.

How can I re-create the root-account?
And/or give the account @cees root-rights so I can use that account for administration?