No… The LiteFS proxy, which runs within your Machine, should be doing that itself.
The screenshot from your earlier post does show it listening on the correct port, so I think this might be a case of the outer Fly edge proxy having partially stale metadata.
Could you try changing proxy.target in litefs.yml back to 8081? I know you switched it to 3000 to avoid (seemingly) spurious warnings in the logs, but it looks like it might be more substantive…
Aside: You can see a redirection in detail via:
$ fly ssh console --select # select non-primary
# cat /litefs/.primary
432189ff765432
# curl -i -X POST http://localhost:8080/endpoint
HTTP/1.1 200 OK
Fly-Replay: instance=432189ff765432
Date: Sun, 25 Aug 2024 21:13:48 GMT
Content-Length: 0
The Fly edge proxy will notice the Fly-Replay entry and then send the client’s original request (the one that came in via app-name.fly.dev) to 432189ff765432 instead.