Need an example using MainActivity.kt

[randyramig]

Despite the README saying to modify MainActivity.kt, the only example is for MainActivity.java.

If I do this in MainActivity.kt:

import dev.darttools.flutter_android_volume_keydown

class MainActivity : FlutterAndroidVolumeKeydownActivity()

It doesn't work.

MainActivity.kt:5:22 Packages cannot be imported.
MainActivity.kt:7:22 Unresolved reference 'FlutterAndroidVolumeKeydownActivity'.

Note that I also tried the volume_listener package following their README and it worked with MainActivity.kt.
https://pub.dev/packages/volume_listener