The 401 error code indicates a problem with the authentication credentials.

1. To make sure you have a valid token OAuth 2 token, run the following:

    $ gcloud auth print-access-token
   

2. Verify that the token is supplied in the Authorization HTTP header. It should look like this:

    Authorization: Bearer {TOKEN}
   

If the error persists, try to refresh the token using step 1, as the tokens have a limited time.

Additional Reference stackoverflow.com/a/48734637/14072498