https://wccftech.com/apple-has-released-beta-1-of-ios-12-1-2-and-watchos-5-1-3-to-developers-heres-what-is-new/

Today Apple has seen fit to release the first beta of its upcoming iOS 12.1.2 and watchOS 5.1.3 to developers for testing purposes. The new beta builds are now available to download, so do ready your iPhone and Apple Watch if you’re interested. Let’s dive in to see some more details on what the new beta builds have in store and whether or not Apple has added any forward-facing addition to the table.

If you’re interested in giving iOS 12.1.2 a swing, registered developers can download beta 1 through the Apple Developer Center or via the over-the-air mechanism. Do make sure that a proper profile is installed from the Developer Center.