gitlab.md

config.json:

{
  "oidc_providers": {
		"gitlab": {
			"display_name": "Sign in with GitLab",
			"color": "orange",
			"icon": "gitlab",
			"provider_url": "https://gitlab.com",
			"client_id": "***",
			"client_secret": "gloas-***",
			"redirect_url": "https://your-domain.com/api/auth/oidc/gitlab/redirect",
			"username_claim": "|",
			"order": 3
		}
  }
}

Tutorial in Semaphore UI blog: GitLab authentication in Semaphore UI.