I get an error when registering gitlab runner

Hello My environment is Redhat 7.9 operating system and I installed Gitlab 15.0.2 version on it with omnibus method. Now I ran Gitlab Runner as a docker container for Gitlab CI/CD. However, when I want to register Gitlab runner, the registration process does not take place.

Actually, I can ask you my question. Is it the right method to run Gitlab Runner on the same server with Gitlab omnibus method and run Gitlab Runner as a Docker container? Will this way vir configuration work? Am I getting a register error due to such a configuration. thanks.

ERROR: Registering runner… failed runner=GR1348941xC1Yx7wn status=couldn’t execute POST against https://gitlabtest/api/v4/runners: Post “https://gitlabtest/api/v4/runners”: dial tcp: lookup gitlabtest on server misbehaving
PANIC: Failed to register the runner.