Restrict access to HTTP server

Is there a form of authentication or any way to restrict access to a Languagetool HTTP server? I would like to have the server running on a machine accessible from my laptop from anywhere over the internet, but without leaving the server open to everyone else.

HTTPS ensures that the content of my communication with the server is private, but does not prevent other people from using my LT server.

No, there’s no such option (unless you access the API directly - in that case you could put e.g. nginx in front of the LT server and password-protect that).