How to set up Web Push notifications
In this article you can read how to set up your Web Push notifications inside Newsifier
For Onesignal
If you already have an active Onesignal account you can just copy and paste your API keys inside the CMS. See here how you can do this:
Important: If you were using the Onesignal WordPress plugin you need to change your image and text in your Onesignal account itself.
For Webpushr
In this video you can see all instructions to set up Webpushr inside your CMS: