How to light mobile phone flash from a website

I am new on javascript
I need to open a mobile phone flash on a website.
I searched for this topic, but I just found this information and change little bit but still there is error a "ImageCapture is not defined" I source this error too and couldn't find any thing, So I left code below

thank you for lookin at :)

//Test browser support
function doFunction() {
const SUPPORTS_MEDIA_DEVICES = 'mediaDevices' in navigator;

if (SUPPORTS_MEDIA_DEVICES) {
    //Get the environment camera (usually the second one)
    navigator.mediaDevices.enumerateDevices().then(devices => {

        const cameras = devices.filter((device) => device.kind === 'videoinput');

        if (cameras.length === 0) {

            throw 'No camera found on this device.';
        }

        const camera = cameras[cameras.length - 1];
        console.log("sad1");
        // Create stream and get video track
        navigator.mediaDevices.getUserMedia({
            video: {
                deviceId: camera.deviceId,
                facingMode: ['user', 'environment'],
                height: {ideal: 1080},
                width: {ideal: 1920}
            }
        }).then(stream => {
            const track = stream.getVideoTracks()[0];
            console.log(track);
            //Create image capture object and get camera capabilities
            const imageCapture = new ImageCapture(track)
            const photoCapabilities = imageCapture.getPhotoCapabilities().then(() => {
                console.log("sad3");

                //todo: check if camera has a torch

                //let there be light!
                const btn1 = document.querySelector('.switch1');
                const btn2 = document.querySelector('.switch2');

                btn1.addEventListener('click', function(){
                    console.log("dsfsdf");

                    track.applyConstraints({
                        advanced: [{torch: true}]
                    });
                });
                btn2.addEventListener('click', function(){
                    track.applyConstraints({
                        advanced: [{torch: false}]
                    });
                });
            });
        });
    });




    //The light will be on as long the track exists


}



    console.log("sddsf");

}

<!doctype html>
<html class="no-js" lang="">
    <head>
        <meta charset="utf-8">
        <meta http-equiv="x-ua-compatible" content="ie=edge">
        <title>click ob/of to open/close flash</title>
        <meta name="description" content="">
        <meta name="viewport" content="width=device-width, initial-scale=1">

        <link rel="stylesheet" type="text/css" href="site.css">

        <script src="site.js"></script>

    </head>
    <body>
    <input id="switch1" type="button" value="On" onclick="doFunction();" />
    <input id="switch2" type="button" value="Off" onclick="doFunction();" />
        <h1>Hello World</h1>

    </body>

</html>

but when I try it at localhost, I got this error:-

but it work properly at https://jsfiddle.net/Mustafagulsoy/7efsb0rk/ if anyone can help me, I will be grateful

Solution

I solve my problem it cause because my html code doesnt find javascript code I left the last version my code, if you dont understand somewhere you can ask me again

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <div class="video-wrap">
        <video autoplay></video>
    </div>



    <div class="controler">
        <button class="switch1">On </button>
        <button class="switch2"> Off</button>

    </div>

    <canvas id="canvas" width="640" height="480"></canvas>


    <script>
        navigator.mediaDevices.getUserMedia({
            video: {
                facingMode: 'environment',
            }
        })
            .then((stream) => {
                const video = document.querySelector('video');
                video.srcObject = stream;

                // get the active track of the stream
                const track = stream.getVideoTracks()[0];

                const btn1 = document.querySelector('.switch1');
                const btn2 = document.querySelector('.switch2');
                btn1.addEventListener('click', function(){
                        track.applyConstraints({
                        advanced: [{torch: true}]
                    });
                });
                btn2.addEventListener('click', function(){
                    track.applyConstraints({
                        advanced: [{torch: false}]
                    });
                });




            })
            .catch(err => console.error('getUserMedia() failed: ', err));
    </script>

    <title>Title</title>
</head>
<body>

</body>
</html>