I am unable to get list of namespaces using rest api and rest end point is https://<localhost>:8001/api/v1/namespaces

Using this kubernetes document:

I am using postman. I will repeat the steps:

1. Created a user and given cluster admin privileges:

kubectl create serviceaccount exampleuser

2. Created a rolebinding for our user with cluster role cluster-admin:

kubectl create rolebinding <nameofrolebinding> --clusterrole cluster-admin --serviceaccount default:exampleuser

3. Checked rolebinding using:

kubectl describe rolebinding <nameofrolebinding>

4. Now by using:

kubectl describe serviceaccount exampleuser kubectl describe secret exampleuser-xxxx-xxxx

I will use token I got here to authenticate postman.

GET https://<ipofserver>:port/api/v1/namespace

AUTH using bearer token.

Expected result to list all namespaces in cluster. like kubectl get namespaces. But got a warning as follows.

{
    "kind": "Status",
    "apiVersion": "v1",
    "metadata": {},
    "status": "Failure",
    "message": "namespaces is forbidden: User \"system:serviceaccount:default:exampleuser\" cannot list resource \"namespaces\" in API group \"\" at the cluster scope",
    "reason": "Forbidden",
    "details": {
        "kind": "namespaces"
    },
    "code": 403
}

I have used "cluster-admin" clusterrole for the user, still getting authentication related error. please help.