Azure: Authorization fail when trying to create notification hub namesapce

Am using the node.js SDK to call the Azure notification hub api, I registered an application using Azure Active directory also i created a resource group and added my user to it as owner. But am getting this error when calling the api:

AuthorizationFailed

The client '333848ca-f996-XXXXXXXXXXXX' with object id '333848ca-f996-XXXXXXXXX' does not have authorization to perform action 'Microsoft.NotificationHubs/namespaces/write' over scope '/subscriptions/ef8e8e-XXXXXXXXXXXX/resourceGroups/notificationGroup/providers/Microsoft.NotificationHubs/namespaces/namespaceapp1

The code:

  MsRest.loginWithServicePrincipalSecret(
    My Subscription ID,
    My Application Secret Key,
    My Directory ID, // found under AD -> properties 
    (err, credentials) => {
      if (err) throw err;
      // eslint-disable-next-line 
      const client = new notificationHubsClient(credentials, AZURE_SUBSCRIPTION_ID);
      const createNamespaceParameters = {
        location: AZURE_LOCATION,
        tags: {
          tag1: 'value1',
          tag2: 'value2',
        },
      };
      client.namespaces.createOrUpdate(AZURE_RESOURCE_GROUP_NAME, req.body.name, createNamespaceParameters,
        (error, result) => {
          if (error) {
            res.send(error);
          }
          console.info(`Namespace created${JSON.stringify(result, null, ' ')}`);
          res.send('app created');
        });
    },
  );

via user3462064