The error you are receiving points to be a problem with RBAC(Role-based access control) permissions, looks like the service account used by the pod does not have enough permissions.
Hence, the default service account within the namespace you are deploying to is not authorized to mount the secret that you are trying to mount into your Pod.
You can get further information on the following link Using RBAC Authorization
You also can take a look at the Google’s documentation
For example, the following Role grants read access (get, watch, and list) to all pods in the accounting Namespace:
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
namespace: accounting
name: pod-reader
rules:
- apiGroups: [""] # "" indicates the core API group
resources: ["pods"]
verbs: ["get", "watch", "list"]
Also you can take a look at the following similar cases Case in Reddit, StackOverflow case