If you open Ratel from the Cloud Panel. It will create an API Key and inject on the fly.
If you wanna use Ratel from your end. You have to go in the panel and create an Admin or User Key.
BTW, Have you tried X-Dgraph-AuthToken?
Cuz you have a login. The namespaces are ACL Login bound. Once you log in with the user of that namespace, you will be redirected to the GraphQL of that namespace.
I’m not sure. Dedicated servers tend to have a different logic than shared servers. I never used a dedicated one.