Snippet to enable torch on running video track in Html5Qrcode library

html5_qrcode.enableTorch.ts

let constraints: MediaTrackConstraints = {
    "torch": true,
    "advanced": [{ "torch": true }]
};

await html5Qrcode.applyVideoConstraints(constraints);
let settings = html5Qrcode.getRunningTrackSettings();

if (settings.torch === true) {
    // Torch was indeed enabled, succeess.
} else {
    // Failure.
    // Failed to set torch, why?
}