http://eweiibe6tdjsdprb4px6rqrzzcsi22m4koia44kc5pcjr7nec2rlxyad.onion/help/administration/integration/plantuml.md
Enable PlantUML integration
After configuring your local PlantUML server, you're ready to enable the PlantUML integration:
Sign in to GitLab as an Administrator user.
On the left sidebar, at the bottom, select Admin .
On the left sidebar, go to Settings > General and expand the PlantUML section.
Select the Enable PlantUML checkbox.
Set the PlantUML instance as https://gitlab.example.com/-/plantuml/ ,
and select Save changes .