https://www.npmjs.com/package/qr-detector
https://github.com/stefansundin/qr-detector.js
React demo: https://github.com/stefansundin/qr-detector.js/tree/react-demo
Installing a service worker makes this demo page available offline. You can also add the page to your home screen on certain platforms.
Select an image or video file (or drag and drop), or use the button below to use your webcam or screen capture. All detection is done in the web browser.
Tip: get a sample image from a search engine to test with.