CalculateCameraBox.cs

using System.Collections.Generic;
using UnityEngine;

public class CalculateCameraBox : MonoBehaviour
{
    private Camera _camera;
    private EdgeCollider2D _camEdgeCollider;
    private float _sizeX, _sizeY, _ratio;

    [SerializeField] private bool isPortrait;
    [SerializeField][Range(1f,10f)] private float sizeRatioX = 2, sizeRatioY = 2;
    public void Calculate()
    {
        _camera = GetComponent<Camera>();
        if (!TryGetComponent(out _camEdgeCollider))
        {
            Debug.LogWarning("Edge Collider not Founded");
            return;
        }
        _ratio = isPortrait ? (float)Screen.width / (float)Screen.height : (float)Screen.height / (float)Screen.width;

        _sizeY = _camera.orthographicSize * 2;
        _sizeX = _sizeY * _ratio;

        List<Vector2> points = new(5)
        {
            new Vector2(-_sizeX /sizeRatioX, -_sizeY /sizeRatioY),
            new Vector2(_sizeX / sizeRatioX, -_sizeY /sizeRatioY),
            new Vector2(_sizeX / sizeRatioX, _sizeY /sizeRatioY),
            new Vector2(-_sizeX /sizeRatioX, _sizeY/sizeRatioY),
            new Vector2(-_sizeX /sizeRatioX, -_sizeY /sizeRatioY),
        };

        _camEdgeCollider.SetPoints(points);
    }
}

CalculateCameraBoxEditor.cs

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(CalculateCameraBox))]
public class CalculateCameraBoxEditor : Editor
{
    public override void OnInspectorGUI()
    {
        base.OnInspectorGUI();

        CalculateCameraBox calculateCameraBox = (CalculateCameraBox)target;

        if (GUILayout.Button("Create"))
        {
            calculateCameraBox.Calculate();
        }
    }
}