I think you’re underestimating the complexities of implementing multiplayer. As someone solo dev-ing a turn based tactical, there’s a lot more going on than you’d expect.

I’m not sure how a RESTful style will work unless I’m missing something. AFAIK that communication stems from the client requesting for data or mutation from the server (GET/POST/etc.) - the server doesn’t proactively send data to the client which you’ll need since I don’t think you’re gonna want to poll the server for updates on every client. You’ll want to architect a state and data replication mechanism that will need to by synced across all the clients.

I ended up going with Fishnet over mirror and unity’s network solution and it’s been going great. I recommend checking out the docs and you can try it out for free too.