Fix Google Pay not working on Chrome

I encountered a weird problem that clicking a "Buy with Google Pay" button flashes a Processing dialog and immediately closes/fails. Stranger that Safari was working fine, while Chrome remains broken for me for several weeks.

Opening the browser console reveals a hint:

NotSupportedError: The payment method "https://google.com/pay" is not supported.

The problem occurs because the payment handlers option in Chrome settings has been turned off, open chrome://settings/content/paymentHandler and change the option to "Sites can install payment handlers"

Alternatively, adding pay.google.com to "Allowed to install payment handlers" is also enough to re-enable Google Pay support.

You can use this demo site to verify that Google Pay is working.