If you are running proxmox then you can use tteks NPM lxc script and add the crowdsec script on top of that. Took me about 2 minutes with the downside of running something someone else set up instead of going step by step.

I am guessing you used one of tteks automated lxcs scripts which unless you manually configure will set up passwordless ssh login. Which only works using the proxmox shell. Just start over and read over your options. You can set up manual ssh credentials when you 1st set up the lxc by not selecting default settings.