Kubernetes and microk8s join error: Joining failed

I am trying to learn microk8s. I installed 3 Ubuntu in my virtual box. I installed the microk8s on each of these virtual machines. I want machines in the form of master node and 2 worker nodes to communicate with each other. I tried to use

microk8s add-node 

command in first machine. And in the second machine, I tried to join this as a worker. But it does not work. I gave this error:

microk8s join<>/<> --worker

Connecting cluster at
Joining cluster failed. Could not verify the identity of User '--skip-verify' to skip server certificate check.

If I tried to microk8s join --skip-verify<>/<> --worker I got an error which is

Connection failed. Invalid token (500).

How could I join the node from second virtual machine? Could you help me? Thank you for your answer!

Have you configured the K8s with Kubeadm?