[VLM]

Something like Apache Guacamole as a https web to SSH "something" gateway?

Go to http-something in your web browser which is a Guacamole install and log in to Guacamole as "guest" / "guest" then in guac the only connection option is some SSH login that'll appear in your web browser

As a warning people have tried to supply "nethack as-a-service" or whatever and people are really creative about gaining shell access somehow anyway, via buffer overflows or who knows what. You can do it, just be careful.