You've been able to send money via Google Pay for a while now in the US and India, but so far, you could only protect your transactions with a PIN. The latest Google Pay version, 2.100, is looking to change that. It's adding support for Android 10's new biometrics API so you can use your fingerprint or face to authenticate transactions instead.
The update adds an option to use biometrics for authentication in the Sending money settings. Previously, you could only require a code before sending money and there was no way to use your fingerprint or face. The new toggle now lets you authenticate with your unique features along with the PIN. We already knew this option was coming when we examined Google Pay's code earlier this year.
Left: No biometrics option in v2.99 or earlier. Middle & Right: New biometrics toggle and face unlock in action.
This change should only affect the sending money aspect of the app. For NFC payments in store, you still simply need to unlock your phone as usual.
You can get the update to version 2.100 once it rolls out on the Play Store or by sideloading it from APK Mirror. Since the API has only been introduced with Android 10, you'll need a device that's already upgraded to the latest OS version. It might be available on Android 9, too, judging from Google's documentation.