No worries. You posted under the “hass.io” category, so I assume you’re using the Hass.io install for Home Assistant? If so…
How did you “install” SSH as you described? If you are using this Add-On:
Then you need to configure it in order to use it:
You do this configuration on your Home Assistant web interface by going to Hass.io and selecting SSH - Secure Shell and updating the Config window as described.
In that Config window, one of the things you specify is the username, which I called out because you posted that you tried to SSH in to [email protected], which won’t work, unless the username you specified is root. I had forgotten mine, so I had to check what I had used, then it worked for me (I don’t SSH often). There are other things to configure, so I’m assuming you’ve done all that, or it won’t work.
Regarding “docker”, the Hass.io installation is a prepackaged operating system that runs virtual environments called dockers. Each docker is independent of the OS and other dockers (they’re not directly aware of each other). If you SSH in to the OS (using an SSH shell at the OS level) you won’t be interacting with the Hass.io docker unless you know where to find the files for it. The Add-on I mentioned above runs within the Hass.io docker, so if you use that SSH shell you’re in the docker and directly interacting with Hass.io. To differentiate the SSH you are connecting to, you use a port when configuring SSH, and specify that port when connecting. The default port on the Add-on is 22. The default port for the OS in Hass.io is 22222.
So, to SSH in to the Add-on I use: ssh {username}@hassio.local -p 22. To SSH in to the Hass.io OS-level I use: ssh [email protected] -p 22222. For now, I’d recommend you stick with the Add-on.
Hope this helps.