I have an android app but all it is, is a Webview which is displaying my website (much easier to maintain an update)
What I want do is call functions like making a payment through Google or downloading data to the app itself
Is there anyway through php to do such a thing? I searched various things on Google but they just return apps, and I'm looking for a code or maybe some sdk
PHP code runs on your server, not on the client, so there is no way to do it that way.
This will help: https://developer.android.com/guide/webapps/webview.html