How to initialize AASSET_Manager on SDL android app

How do i use assetmanager.h from an SDL android app from android studio? Do i have to edit SDL_Activity.java? With what? Calling the functions from assetmanager.h crashes the app. Someone then commented that i need to get the java object or something along those lines before using the API.

I've been trying for weeks without success... Aassetmager_openDir will crash the app on Android. I have already added the -landroid to the mk file... C++, on Android studio and using the SDL2 library...