WebPush can be used to send notifications to endpoints which server delivers Web Push notifications as described in the Web Push protocol. Browsers need to verify your identity. A standard called VAPID can authenticate you for all browsers. You'll need to create and provide a public and private key for your server. These keys must be safely stored and should not change.
Click ‘GENERATE’ button to generate VAPID keys and use them to authenticate you.
Based on the web-push-libs/web-push-php library.