Determine which version of GitLab Self-Managed you have
If you add
/api/v4/version to the end of the URL for your GitLab Self-Managed
instance the resulting page will show you your version information. For example,
our URL is
http://gitlab.codestream.us/api/v4/version, which results in:
If you would like to use CodeStream's integration with merge requests from GitLab Self-Managed, you'll need version 12.10 or later.