It's a pity that some GitLab users have removed Staticman from their repo. I saw demand for Staticman from Framagit users. Therefore, after two days of testing, another API instance for Framagit has been created at https://staticman-frama.herokuapp.com. (Edit: typo edited, please see my comment below.)
The default GitLab base URL is set to “https://gitlab.com". To provide Staticman support for a self-hosted GitLab service, another Staticman API server has to be set up.