This means K3s isn't running. Try systemctl start k3s in command line. If this isn't working then check the k3s_daemon.log in /var/logs to find out why its not starting.
May 29 17:53:15 truenas k3s[2324998]: time="2022-05-29T17:53:15+08:00" level=error msg="Failed to connect to proxy" error="websocket: bad handshake"
May 29 17:53:15 truenas k3s[2324998]: time="2022-05-29T17:53:15+08:00" level=error msg="Remotedialer proxy error" error="websocket: bad handshake"
May 29 17:53:36 truenas k3s[2325373]: E0529 17:53:36.771686 2325373 kubelet.go:2001] "Skipping pod synchronization" err="[container runtime status check may not have completed yet, PLEG is not healthy: pleg has yet to be successful]"
May 29 17:53:36 truenas k3s[2325373]: E0529 17:53:36.871982 2325373 kubelet.go:2001] "Skipping pod synchronization" err="[container runtime status check may not have completed yet, PLEG is not healthy: pleg has yet to be successful]"
May 29 17:53:37 truenas k3s[2325373]: E0529 17:53:37.057798 2325373 kubelet.go:1431] "Failed to start ContainerManager" err="failed to build map of initial containers from runtime: no PodsandBox found with Id '03fedcbce181d2f238239ecd81549fc16190c6d522b72dcfe0696e686daea366'"
some reason