When I ran the following script, I got an error.

Assets/Scripts/Result_script.cs (10,22): error CS0234: The type or namespace name'Imaging' does not exist in the namespace'System.Drawing' (are you missing an assembly reference?)

Could you please tell me how to add System.Drawing to the vistual studio code? Thank you.

Execution environment: mac mojave, vs code

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using SocketIO;
using System;
using System.Drawing;
using UnityEngine.UI;
using System.IO;
using System.Drawing.Imaging;
public class Result_script: MonoBehaviour {
    //abridgement··
}