Issue at OnResponse callback in MainActivity.kt

Question

Would you help me please? There is an error refer to OnResponse in MainActivity.kt

Can you find where is the issue?

FATAL EXCEPTION: main Process: com.example.movieapp, PID: 22955 java.lang.NullPointerException at com.example.movieapp.MainActivity$getMovieData$1.onResponse(MainActivity.kt:39) at retrofit2.DefaultCallAdapterFactory$ExecutorCallbackCall$1.lambda$onResponse$0$retrofit2-DefaultCallAdapterFactory$ExecutorCallbackCall$1(DefaultCallAdapterFactory.java:89) at retrofit2.DefaultCallAdapterFactory$ExecutorCallbackCall$1$$ExternalSyntheticLambda0.run(Unknown Source:6) at android.os.Handler.handleCallback(Handler.java:942) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loopOnce(Looper.java:201) at android.os.Looper.loop(Looper.java:288) at android.app.ActivityThread.main(ActivityThread.java:7872) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)

class MainActivity : AppCompatActivity() {

private var _binding : ActivityMainBinding? = null
private val binding get() = _binding!!

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    _binding = ActivityMainBinding.inflate(layoutInflater)
    setContentView(binding.root)

    val layoutManager: RecyclerView.LayoutManager = LinearLayoutManager(this)

    binding.rvGenresList.layoutManager = layoutManager
    binding.rvGenresList.setHasFixedSize(true)
    getMovieData { movies: List<Movie> ->
        binding.rvGenresList.adapter = MovieAdapter(movies)
    }
}

private fun getMovieData(callback: (List<Movie>) -> Unit){
    val apiService = MovieApiService.getInstance().create(MovieApiInterface::class.java)
    apiService.getMovieList().enqueue(object : Callback<MovieResponse> {
        override fun onResponse(call: Call<MovieResponse>, response: Response<MovieResponse>) {
            return callback(response.body()!!.movies)
        }

        override fun onFailure(call: Call<MovieResponse>, t: Throwable) {
            TODO("Not yet implemented")
        }

    })
}

}

I'm trying to use recyclerview with binding and using API from moviedb.org.

This is my first time to use it. So, is there I need to do to fix this and render the list to screen?

Thank you