How to use specific UDP ports for pixelstreaming‘s webRTC

I am using UE 4.27.2 ,I found the UDP port used by the pixel streaming for webrtc is randomly selected, and the official document does not have any thing about change the webrtc ports range . I found that the browser can set ports range from the policy setting WebRtcUdpPortRange. Is there any way to restrict it from the UE side?