Firebase Push Notification App

We have PHP based web application deployed on AWS/Unix and exposed as https://sample.url. Users access it via Android App (we have turned into Android App using WebView) and also via desktop browser. We need Android push notification functionality, which will send messages / notification to respective client Apps. E.g. if particular user gets message in their Inbox or Chat message via Website or PHP code, we notify that particular App user with Push notification and when they click or open it, the app is opened with particular URL e.g. [login to view URL] Sample code / Tutorials can be referred at : [login to view URL] [login to view URL] [login to view URL]@salonikogta/beginners-guide-to-implementing-push-notifications-in-android-e896ef54b831 Eventually we will modify the whole website into Native/Cross Platform App in multiple phases, but this is the first assignment for which we are proposing $25, which includes setting up code on Server and making APK to test it. Next phases will be $ 10 each for each form or page on the website. When you Bid, write Firebase App at the start, so we know you read this assignment, understood it and are not just sending me message saying let's get more details over chat. If that's the case, you are not the one we are looking for. If you have better solution or approach, We are willing to listen.