Register Docker Build Runner

I want to register my build runner that is setup in a Windows docker image.

I managed to specify setup the image but when I register the runner I get an error:

Step 9/14 : RUN gitlab-runner.exe register --non-interactive --url https://gitlabserver --registration-token SECRET --executor shell --name win_docker_runner --locked False --run-untagged False --docker-privileged false --limit 0 --tag-list windows7
—> Running in bacb97740f7e
ERROR: Registering runner… failed runner=JJrF6xR6 status=couldn’t execute POST against https://gitlabserver/api/v4/runners: Post https://gitlabserver/api/v4/runners: x509: certificate signed by unknown authority
PANIC: Failed to register this runner. Perhaps you are having network problems

I guess I need to register the public ssh key on the gitlab server.
Do I specify the host machines, docker’s or the windows in dockers generated ssh key?