Intellij Java remote debug with SSH tunnel

This is the simplest explanation how to do it:
https://arjon.es/2014/remote-debug-of-a-java-app-using-ssh-tunneling-without-opening-server-ports/ (it is a bit confusing, as is uses localhost for both remote and local)
and
https://www.revsys.com/writings/quicktips/ssh-tunnel.html which clearly runs the ssh command locally forwarding to remote and highlights the role of -N parameter)
also worth reading:
https://www.jetbrains.com/help/idea/remote-debugging-via-ssh-tunnel.html#troubleshooting this is about PHP debugging

SSH tunneling explained visually https://www.youtube.com/watch?v=N8f5zv9UUMI

this command does the trick:
ssh -f user@personal-server.com -L 9999:personal-server.com:9999 -N