Reported same here a while ago, thought it only happenned on pushbullet:
Notification to external web applicaiton
I have a web app running in different server, for forum i want to use Nodebb. Is there any way to send notification to my web app when any post created or any one replied, commented to my post.
You can use OneSignal plugin for push notifications and integrate it into your web app.
Thank you @meetdilip, any example or documentation for reference.