https://wccftech.com/new-surface-firmware-updates-are-available-for-several-devices/

Microsoft has released fresh firmware updates for several of its Surface products, including Surface Book 3, Surface Laptop 1st Gen, Laptop Go, Surface Pro 5,  and Pro 6. These updates focus on device stability along with addressing critical security vulnerabilities. Earlier in the week, the company also released updates for Surface Laptop 3 (Intel), Laptop 4, and Surface Book.

The following updates are available for Surface Book 3 running Windows 10 May 2019 Update, version 1903, or greater.