Variable Switch on Button Press

Hi, i want to make a Camera-Switcher in my Script.
But my script is not working.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using OpenCvSharp;

public class FaceDetector : MonoBehaviour
    public int Camera;
    WebCamTexture _webCamTexture;
    // Start is called before the first frame update
    void Start()
        WebCamDevice[] devices = WebCamTexture.devices;

    // Update is called once per frame
    void Update()
        GetComponent<Renderer>().material.mainTexture = _webCamTexture;
        _webCamTexture = new WebCamTexture(devices[Camera].name);

Assets\Scripts\FaceDetector.cs(23,44): error CS0103: The name ‘devices’ does not exist in the current context

What am I missing here?

devices[Camera].name should be WebCamTexture.devices[Camera].name

You cant use local variables from an entirely different scope.