https://wccftech.com/latest-surface-firmware-update-is-available-for-surface-book-2/

Surface Book 2 is the latest of the Surface devices receiving new updates. Microsoft has recently delivered updates for a number of Surface products, including Surface Book 3, Surface Laptop 1st Gen, Laptop Go, and others. The Surface Book 2 updates were released last week and are available for devices running Windows 10 May 2019 Update, version 1903 (19H1), or greater.

These latest firmware updates address critical security vulnerabilities, improve device stability and camera and audio reliability.