Numerous forum posts and documentations specify extracting login info for the Kubernetes install from ~/.kube/config.
The problem I found: mine doesn't have a proper user account, it specifies a name and a token.
How do I get the account name so I can use the kubernetes-cockpit UI? Surprisingly there appears to be nothing on that topic - what to do if the config doesn't contain an account.
It depends on how you use Cockpit. According to cockpit official page:
Used in a standard cockpit session:
If a user is able to use kubectl successfully when at their shell terminal, then that same user will able to use Kubernetes dashboard when logged into Cockpit
I suppose this is your scenario, so if you didn't change default settings, the cockpit will look for .kube/config itself, i.e. you should be able to login without specifying your account.