Access Private Docker Image Repository - Not Self-Hosted

Hi, first of all. I'm new to Traefik so please excluse if this is a stupid question.
Of cause i first searched the web for information but did not find any relevant article to my question.

Following Situation:
I am using Traefik 2.3 in Docker Swarm Mode. I want to access docker images that are hosted on GitLab (Private Repository). I can pull and rum them AFTER AUTHORIZATION via commandline - No issue.

Traefik does not know my credentials for accessing my private docker image repository. I only found articles how to publish an private docker repository behind traefik, but i dont not want to do this. I just want to use my existing respository in GitLab.

How can i tell Traefik's Docker Deamon that it has to login with "credentials abc" on Service X?

Thanks in advance

Marco Griep

I found it. i just have to pass "--with-registry-auth" next to the docker stack command.

Not a traefik related issue. This is 100% docker.