How do I associate file extensions with default apps?
Android is HORRIBLE at this. For the most part you can't. There is no File Type Manager in Android at ALL. Complete garbage. Walk away. Every File Explorer I use shows different lists of apps for different extensions. Even the built in Android one. And it hides MOST apps from default apps open links. etc. So Android thinks most apps can't open local files. Even though they can when using Activity manager.