AudioPlaybackCapture android 10 with MediaProjection screen capture not working

Question

I am trying to capture screen using MediaProjections screen capture api with AudioPlaybackCapture in android 10. but i am unable to do that. please help me here. AudioPlaybackCapture api repository i am following this AudioPlaybackCapture api code with Screen capture. video is getting record but there is not audio.

 fun initRecorder() {
        //   if (mMediaRecorder == null) {
        mMediaRecorder = MediaRecorder().apply {
            setVideoSource(SURFACE)
            try {
                // setAudioSource(MIC)
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
                    //startAudioCapture()
                    val config = AudioPlaybackCaptureConfiguration.Builder(this)
                        .addMatchingUsage(AudioAttributes.USAGE_MEDIA) // TODO provide UI options for inclusion/exclusion
                          .addMatchingUsage(AudioAttributes.USAGE_UNKNOWN)
           .addMatchingUsage(AudioAttributes.USAGE_GAME)
                        .build()

                    /**
                     * Using hardcoded values for the audio format, Mono PCM samples with a sample rate of 8000Hz
                     * These can be changed according to your application's needs
                     */
                    val audioFormat = AudioFormat.Builder()
                        .setEncoding(AudioFormat.ENCODING_PCM_16BIT)
                        .setSampleRate(8000)
                        .setChannelMask(AudioFormat.CHANNEL_IN_MONO)
                        .build()

                    audioRecord = AudioRecord.Builder()
                        .setAudioFormat(audioFormat)

                        // For optimal performance, the buffer size
                        // can be optionally specified to store audio samples.
                        // If the value is not specified,
                        // uses a single frame and lets the
                        // native code figure out the minimum buffer size.
                        .setBufferSizeInBytes(BUFFER_SIZE_IN_BYTES)
                        .setAudioPlaybackCaptureConfig(config)
                        .build()
                    mMediaRecorder!!.setAudioSource(audioRecord!!.audioSource)

                    // setAudioEncoder(AAC)
                   // val rate = 44100
                   // setAudioSamplingRate(rate);
                  /*  if (audioRecord != null) {

                    }*/
                } else {
                    setAudioSource(MediaRecorder.AudioSource.MIC)
                    setAudioEncoder(AAC)
                    val rate = 44100
                    setAudioSamplingRate(rate);

                }

            } catch (t: Throwable) {
            }
            setOutputFormat(MPEG_4)

            val frameRate = 30
            setVideoFrameRate(frameRate)
            setVideoEncoder(H264)
            //
            setVideoSize(DISPLAY_WIDTH, DISPLAY_HEIGHT)

            val videoBitRate = 8000000
            setVideoEncodingBitRate(videoBitRate)

            val bitDepth = 16;
            val sampleRate = 44100
            val bitRate = sampleRate * bitDepth;

            setAudioEncodingBitRate(bitRate)
            //  setAudioSamplingRate(sampleRate);

            val filePath = getFilePath()
            setOutputFile(filePath)

            try {
                prepare()
            } catch (fe: FileNotFoundException) {
                print("Failed to prepare the media recorder. ${fe.message}")
            } catch (t: Throwable) {
                print("Failed to prepare the media recorder. ${t.message}")
            }
        }
    }