Cs0234 unity как исправить

I’m trying to make a simple button perform an action when pressed. Initially I was using vscode, but as I couldn’t solve the problem, I switched to visual studio 2017. For some reason the error persists.

The button has been removed from this link:

https://www.c-sharpcorner.com/article/unity-change-scene-on-button-click-using-c-sharp-scripts-in-unity/

Button code (internet sketch):

using System.Collections;  
using System.Collections.Generic;  
using UnityEngine;  
using UnityEngine.SceneManagement;

public class SceneChanger: MonoBehaviour {  
    public void Scene1() {  
        SceneManager.LoadScene("Scene1");  
    }  
    public void Scene2() {  
        SceneManager.LoadScene("Scene2");  
    }  
    public void Scene3() {  
        SceneManager.LoadScene("Scene3");  
    }  
}

Button code (my code):

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
using System.Windows.Forms;

public class botaoJogar : MonoBehaviour
{
    public Button btn_Jogar;

    void Start()
    {
        Button btn = btn_Jogar.GetComponent<Button>();
        btn.onClick.AddListener(TaskOnClick);
    }

    void TaskOnClick()
    {
        Debug.Log("You have clicked the button!");
    }
}

Image of the construction in unity:

Before, I was able to solve the CS0236 error using the answers from this link:

https://stackoverflow.com/questions/2883505/the-type-or-namespace-name-button-could-not-be-found-are-you-missing-a-using

The answer says to add the line using System.Windows.Forms; to the button code, but for some reason, now in visual studio, this error doesn’t go away.

Errors:

Assetsbotajogar.cs(4,22): error CS0234: The type or namespace name
‘Forms’ does not exist in the namespace ‘System.Windows’ (are you
missing an assembly reference?)

Assetsbotajogar.cs(8,12): error CS0246: The type or namespace name
‘Button’ could not be found (are you missing a using directive or an
assembly reference?)

Some community links, which I accessed:

https://stackoverflow.com/questions/42000798/how-do-i-add-assembly-references-in-visual-studio-code

https://stackoverflow.com/questions/49805204/adding-reference-to-another-project-from-visual-studio-code

https://stackoverflow.com/questions/2883505/the-type-or-namespace-name-button-could-not-be-found-are-you-missing-a-using

https://stackoverflow.com/questions/47412796/system-windows-forms-assembly-reference-in-vs-code

https://stackoverflow.com/questions/46582847/creating-a-windows-forms-application-in-c-sharp-using-dotnet-new

https://stackoverflow.com/questions/40562192/windows-form-application-on-visual-studio-code

https://stackoverflow.com/questions/48496542/forms-does-not-exist-in-the-namespace-system-windows

Other links:

https://docs.microsoft.com/en-us/visualstudio/ide/how-to-add-or-remove-references-by-using-the-reference-manager?view=vs-2019

https://docs.microsoft.com/pt-br/dotnet/csharp/language-reference/compiler-messages/cs0246

I don’t know what to do anymore, I feel like I tried to do everything I could, but windows forms simply don’t work. Visual studio 2017 has no bugs, just unity.

Installation I did in visual studio 2017: