You should be able to start up your old container with
./launcher start app
That will get you back up.
It’s beyond end of life by almost two years. I recommend that you spin up a new virtual machine and Move a Discourse site to another VPS with rsync.
I don’t recommend it, but several people have reported success lately running a dist-upgrade.
If the rsync seems too complicated, just copy over your app.yml and a backup. Do a rebuild, and restore the backup. You will need to find a way to move the app.yml and the backup file from the old server to the new one.
If and OS upgrade or move to a new VM is more than you want to take on and you’d like paid support, you’re welcome to email me (address is on my user card).