Code collab for teaching non-CS majors web JavaScript/HTML/CSS?

I teach a college-level intro to html/css/js to mostly business majors. We can get by with VSCode doing livereload on a single machine or liveshare on multiple machines, but not both because Univ IT blocks liveshare's public port broadcast. Teaching them Git would burn 1-2 class sessions, but might be worth it -- not sure.

Is there a way to satisfy these reqs?

1. Provides live-sharing (2+ students code from separate machines in the same file)

2. Supports auto-reload on each machine without public port binding (Univ IT blocks port broadcast)

3. Is an IDE or IDE extension

4. Keeps some sort of version history

5. Syncs a local copy of the files on each machine* (nice to have)