IsTargetHardMuted 

Namespace: SynicSugar.RTC

public bool IsTargetHardMuted(UserId target)
public bool TryGetIsTargetHardMuted(UserId target, out bool isMuted)

Description 

Whether the target is hard-muted in this session.
This is valid only for Lobby Host. Guests don't know user's hard-muted.

using SynicSugar.P2P;
using SynicSugar.RTC;
using UnityEngine;

public class VCSample : MonoBehaviour {
    public void GetMuteState(UserId target){
        string state = RTCManager.Instance.IsTargetHardMuted(target) ? "Muted" : " NotMuted";
        Debug.Log($"{target} is {state}");
    }
}