Making an Interactive Snippet to All Members Logged into GitLab (Self-Hosted)

I made a Markdown snippet with a task list.

i.e.

## User 1
- [ ] Task 1
- [ ] Task 2

## User 2
- [ ] Task 1
- [ ] Task 2

None of the users can tick their tasks. I (who created the snippet) can edit the snippet and tick each completed task.

Why is this not interactive?