I've been trying to enable Redmine integration so I consulted Integration With Issue Trackers.
I've set the changed the issue_server_link to point towards our Redmine instance:
issue_pat issue_prefix are set to their respective default values. But I still get https://myissueserver.com/app/repo_name/issue/1221.
Also: the documentation refers to url_pat. This was probably changed to issue_pat?