I need to recover a rancher cluster (using docker setup). I restored from the backup:

docker run  --volumes-from goofy_sinoussi -v $PWD:/backup busybox sh -c "rm /var/lib/rancher/* -rf  && tar pzxvf /backup/rancher-data-backup-v2.7.4-2023-06-19.tar.gz"

Rancher ist starting, I can Login, the cluster shows up but "unavailable" and "Cluster agent is not connected". I know that there is no agent connected, how can i connect an agent ?