Why Notifications Fail in Azure Notification Hub and How to Fix Them

Question

I'm using Azure Notification Hub to send Web Push Notifications. When I use VAPID_PRIVATE_KEY and VAPID_PUBLIC_KEY directly and web-push, notifications work correctly on my website and I receive them on my Windows device. However, when I try to send notifications through Azure Notification Hub, they never arrive.

Below is the payload I'm using with the createOrUpdateInstallation method from the @azure/notification-hubs package.

this.client = new NotificationHubsClient(connectionString, hubName, {enableTestSend: true});

Installation: {
  installationId: 'web_development_cms_entity_m1510251307018297107014171',
  platform: 'browser',
  userId: 'm1510251307018297107014171',
  tags: [
    'development_cms_entity_m1510251307018297107014171',
    'development_cms_entity',
    'development_all'
  ],
  pushChannel: {
    endpoint: 'https://wns2-sg2p.notify.windows.com/w/?token=BQYAAADi9Jraq3kClJiljgQeyDGe%2bvwxDDZ%2byYNlxdOCiuYRR4Ap58FvDOPRLy9uDwoZuXGRR5gSuLYSGcSqRPwuOrAkFx47xDS%2fNIiwoXuM5W0bhPqGgoDqoeBV4g27UqOKRm%2bH%2bjosqoqgx7wBfrvogvyBETUDd%2bO%2fZwNGtuwbJm0JfjunAaGLaZ1Ju3XDUria3%2fVE4OxF2iIg1MEA74youeiNoBjUzQQRgHjxYUaqottJmoSuWqOSCXntuTV8Ub5C7Zyu9aQrdFJPgzheVyw3l44rUAJxi8P%2bv94mo1sKqedfhm08rvqUt5mv54xUlyAo%2bc%2bh556bFvLHfHBROoJz6Ps3',
    p256dh: 'BHY-g-X9L--8XIFcziHcry8tBmHPDd6R7m20r5GKzjDWTCKvDxu5RgmM_1icuG2u2WdWRv5Xrk97L-WAevgKwgQ',
    auth: 'JM_i01UWsinXiATixPK0QQ'
  }
}

I then attempted to send the notification using the sendByTagExpression(tagExpression, payload) function, but it didn’t work as expected. The result was as follows:

 {
    "correlationId": "870ee657-031c-4bc7-a31f-d8a986c917c9",
    "trackingId": "d474baeb-d0ac-4637-a743-2a6164f5fbea",
    "successCount": 0,
    "failureCount": 0,
    "results": [],
    "state": "Enqueued"
  }

Even when I use the Send Test feature in the Azure Portal, I receive the error: "The Notification could not be delivered due to an unknown error." I'm not sure how to resolve this issue, and I would really appreciate any guidance or help from someone who has faced this before.