In order to send push notifications to throw your WordPress site, you need to install the web2application plugin.
1. After installing, Go to “Setting”
2. select and copy your URL that the plugin shows “your-domain.com”
3. login to your web2application account and to to “Push Setting at the left menu”
4. Paste or write your URL that the plugin gave you and click “Create API”
5. the system will generate a special API key for your URL. Copy it and paste to the Plugin Setting ( number 6 on first image)