mediaDevices.getUserMedia has no voice

react-native: 0.61 react-native-webrtc: 1.75.3 RTCView has no voice please help me …
mycode:
mediaDevices.getUserMedia({
audio: true,
video: {
mandatory: {
minWidth: 600, // Provide your own width, height and frame rate here
minHeight: 700,
minFrameRate: 30
},
facingMode: (isFront ? “user” : “environment”),
optional: (videoSourceId ? [{sourceId: videoSourceId}] : [])
}
})
.then(stream => {
// Got stream!
// stream.getTracks()[0].enabled = true
// console.log(stream.getTracks())
// stream.getTracks().forEach((t) => {
// if (t.kind === ‘audio’) t.enabled = !t.enabled;
// });
console.log(stream.getTracks())
this.setState({
streamURL: stream.toURL()
})
})