I used to go via the ngrok way, but thanks for a better-targeted solution.

BTW, just curious is there any other alternative apart from this ?

Gravitational Teleport is frequently used for SSH behind the firewall as well, but also tackles many other aspects of SSH for organizations.

It's Open source! https://github.com/gravitational/teleport https://gravitational.com/teleport/

Disclaimer: I am employed by gravitational