Microsoft Authenticator coming soon to Apple Watch
There were probably enough users that asked for an Authenticator app on Apple Watch to convince Microsoft to make one. Although it's not yet ready, Microsoft announced that it will start a public preview of the Authenticator companion app for Apple Watch.
According to Microsoft, the final version of the app will be released to everyone within the next few weeks. Microsoft Authenticator will allow you to approve sign-in notifications that require PIN or biometric on your Apple Watch without having to use the phone.
The app on Apple Watch should support Microsoft personal, wok, and school account that are set up with push notifications. Naturally, all supported accounts will automatically sync to the Apple Watch.
If you want to try out Microsoft Authenticator on your Apple Watch before the app gets released, you can do so by signing up to become a TestFlight user at the source link.