Mobile browsers block camera access on insecure HTTP addresses. To enable standard camera prompts and just tap Allow directly:
Alternatively, use the Chrome flag workaround:
chrome://flags/#unsafely-treat-insecure-origin-as-secure
in the input box, and relaunch Chrome.
ngrok http 80 on your host PC and open the secure
HTTPS URL on this phone.
Scanner is offline
Tap Start to begin scanning