LocalUserId 

Namespace: SynicSugar.P2P
Class: p2pInfo

public UserId LocalUserId;

Description 

UserID of this local. This Id are assigned by EOS.

using SynicSugar.P2P;
using UnityEngine;
[NetworkPlayer]
public class p2pSample : MonoBehaviour {
    public bool isLocalPlayer;

    void Start(){
        if(isLocalPlayer){
            SetOwnerID(p2pInfo.Instance.LocalUserId);
        }
    }
}