Truenas 12.U8 upgrade issue

I’m running Nextcloud plugin in a Jail on a Truenas server 12.0 - U8
I was on version 21 and I lunched the update plugin and jail and it got stuck because I skipped a version because the update was for 23.01 and I didn’t notice. (In my own opinion this is just ridiculous that skipping version lock me out from my own data - just stop the update with a preliminary check)

Anyway I read I should provide some more information but I’m not able by myself to find those out via the CLI.

I already try to read the post: Updates between multiple major versions are unsupported but TrueNAS uses FreeBSD and I’m simply not able to do what that article wants me to do…I don’t know what command I need to write in the shell to make things work…

can please anyone help me access my files again?