Wait, I'm not really a coder, I just took a code from a tutorial, and added it to my game.
The game itself is pretty easy to port since the game is open source, and I have the source code.
It was pretty easy to port HTML games (if you have the source code) and via the webview method, it worked pretty well.
Well about that "jdk was not found", I think you don't have JDK (Java Development Kit) installed, and for an Android app, you will need Java to export it. (and as well Gradle.)