SSH into some switch or sensor

Hello guy,

After some reading on many post I can’t figure it out with my problem.
I have HA install in a docker on Debian 10 (raspi 4)

I have plex service install on my debian OS and I would like to acces the service via Home Assistant.
I succeded open ssh without password on HA with the terminal. I can communicate with Debian.
Keys are located on /root/.ssh (HA)
My HA user is ‘root’.

But when I try to get Plex info in sensor with :

  - platform: command_line
    name: PlexActive
    command: "ssh [email protected] systemctm is-active plexmediaserver"

I’ve got that :

ERROR (SyncWorker_2) [homeassistant.components.command_line] Command failed: ssh [email protected] systemctm is-active plexmediaserver

And what is realy bother me is that all SSH command work in the terminal in HA