Joining node to pod

I am trying to join my node to my master server. I’ve been following this tutorial to get started: How To Install Kubernetes on Ubuntu 18.04 (Step by Step).

kubeadm join --token --discovery-token-unsafe-skip-ca-verification
[preflight] Running pre-flight checks
error execution phase preflight: couldn’t validate the identity of the API Server: could not find a JWS signature in the cluster-info ConfigMap for token ID “shh31q”
To see the stack trace of this error execute with --v=5 or higher

I try on the master node, kubeadm token list, and get this error message:
failed to list bootstrap tokens: secrets is forbidden: User “system:node:master-node” cannot list resource
“secrets” in API group “” in the namespace “kube-system”: No Object name found