Browser - Keyri Widget Quickstart

1. Serve KeyriQR.html (available here) from the same origin as your login page (e.g., a /public directory)
2. RECOMMENDED: serve everything on your login's origin with the header X-Frame-Options: SAMEORIGIN (examples of how to do so here)
3. Embed an iframe in your login page in the desired DOM element with ./KeyriQR.html as its src

4. Add an event listener to the iframe to listen for messages from it