Default linodes password

I am using linode's kubernetes. When I created a cluster (LKE), it automatically generated VPS (Linodes) for me. So I didn't configure any login credential.

Now, how can I /bin/bash in my VPS?
Via SSH? Then they asked me password.
Via LISH? Ask me login user and password too.

Where is the password? Or other ways to connect? (I tried ssh key of "profile ssh key" but got nothing has been changed.

I don't want to power off my VPS and reset password, because it takes time. I have to do it rolling over each individual one.

Stuck here a week.

Thank you.