Authorization header in google-cloud storage client api

I'm having an problem to specify an access token for authorize my call while using the nodejs client api.

  const gcs = require('@google-cloud/storage')({
    projectId: 'my-project'
  });

  gcs.interceptors.push({
    request: (requestOptions) => {
      requestOptions.headers = requestOptions.headers || {};
      requestOptions.headers['Authorization'] = 'Bearer ' + token.access_token; // it's a string
      return requestOptions;
    }
  });

  const bucket = gcs.bucket('my-buckuet');

  bucket.interceptors.push({
    request: (requestOptions) => {
      requestOptions.headers = requestOptions.headers || {};
      requestOptions.headers['Authorization'] = 'Bearer ' + token.access_token;
      return requestOptions;
    }
  });

  bucket.exists((err, exists) => {
    if (err) {
      console.log(err);
    } else {
      console.log(exists);
    }
  });

I've this error ==> Error: invalid_grant

I try to directly call the API with, postman setting the Authorization header using my generated access token and it works. I don't know how to force the authorization header in the request. any help?

Diego

via Diego Molteni