Ceph RBD failed to get secret

I’m getting the error:

Failed to provision volume with StorageClass "ceph": failed to get admin secret from ["kube-system"/"ceph-admin-key"]: failed to get secret from ["kube-system"/"ceph-admin-key"]

What does the format of the Secret have to be? Does the Key in the key:value pair have to be named something specifically? Like “Key” or “key” or “secret”?

apiVersion: v1
kind: Secret
  name: ceph-secret
  namespace: kube-system
type: "kubernetes.io/rbd"
  # ceph auth get-key client.kube | base64
  key: <your output from above>
  Key: <your output from above>
  secret: <your output from above>