Tramp: needs file notification program on remote machine, what to install?

[Gregor Zattler]

Hello, I'm visiting a directory which is under version
control (git) on a remote machine (still debian/buster)
and get the following error:

Tramp: Opening connection nil for root@fs2 using ssh...done
File notification error: No file notification program found on /ssh:root@fs2:

While I can work with the files there the message is
shown all the time and is at least annoying, and file
notification might be useful.  But I did not find what
to do in the fine manual.

I assume I should instal a helper program on the remote
machine, but AFAIK there are several file system change
notifiers.  Does anyone know which is best/easiest for
tramp?

Thanks, Gregor