import android.app.Application
import com.theapache64.removebg.RemoveBg

class App : Application() {

    override fun onCreate() {
        super.onCreate()

        RemoveBg.init("YOUR-API-KEY")
    }
}

RemoveBg.from(imageFile, object : RemoveBg.RemoveBgCallback {

    override fun onProcessing() {
        // will be invoked once finished uploading the image
    }

    override fun onUploadProgress(progress: Float) {
        // will be invoked on uploading 
    }

    override fun onError(errors: List<ErrorResponse.Error>) {
        // will be invoked if there's any error occurred
    }

    override fun onSuccess(bitmap: Bitmap) {
        // will be invoked when background removed 
    }

})