It was a little over a month ago that Apple Pay Cash made an appearance in iOS and watchOS betas. Although Apple recently debuted the feature with its 11.2 update for iOS, it now makes its way to watches with watchOS 4.2.
The latest update is available for all Apple Watch models and, as mentioned before, brings support for Apple Pay Cash. The feature will allow users to quickly send cash to friends and family with supported devices and software. In order to use it on an Apple Watch, users must first set up the feature on their iOS device. Once this is done correctly, the option to use Pay Cash will appear in Messages and the Wallet app, and will also become available on the Watch.
While the feature is available with the new update, it might not be available in all regions. This is something that you will have to check when you update. You can update the Apple Watch to the latest version of the OS by using the Watch app on your iPhone or iPad, heading to the General menu, and tapping Update.
Source: 9to5Mac