T-Mobile is dropping a new software update to the OnePlus 6T. The update is rolling out as OxygenOS build 9.0.1 (A6013_34_181121). This is the 2nd update for the T-Mobile model.
The update includes an improved camera app, better in-display fingerprint reader algorithm, optimizations in face unlock, improved audio quality, and more. You can see the full changelog in the screenshots below. The update will hit your phone as a 110.2MB file.
To check for the update, go into Settings>System>System updates.