ChangeInputMuteStatus 

Namespace: SynicSugar.RTC

public static void ChangeInputMuteStatus(bool isMute)

Description 

Change input volume status.

using SynicSugar.RTC;
using UnityEngine;
public class MicSetting : MonoBehaviour {
    public void Start(){
        //Mute the device in whole game instead of one session.
        RTCConfig.ChangeInputMuteStatus(true);
    }
}