While issuing command “kubeadm token list”, reporting the below issu

failed to list bootstrap tokens [Get https://192.168.40.132:6443/api/v1/namespaces/kube-system/secrets?fieldSelector=type%3Dbootstrap.kubernetes.io%2Ftoken: x509: certificate signed by unknown authority (possibly because of “crypto/rsa: verification error” while trying to verify candidate authority certificate “kubernetes”)

Perform following step:

cp /etc/kubernetes/admin.conf ~/.kube/admin.conf

export KUBECONFIG=$HOME/.kube/admin.conf

kubeadm token list
TOKEN TTL EXPIRES USAGES DESCRIPTION EXTRA GROUPS
h94rrx.90dkwkukxgcp3635 23h 2018-10-22T08:29:50-07:00 authentication,signing The default bootstrap token generated by ‘kubeadm init’. system:bootstrappers:kubeadm:default-node-token