OnePlus has once again shown its dedication to providing timely software updates, as it's now sending out the Android 10-based Oxygen OS 10 beta build to the OnePlus 6 and OnePlus 6T. The build is exclusive to factory unlocked, non-carrier models.
https://www.notebookcheck.net/The-OnePlus-6-and-6T-are-now-receiving-the-Android-10-beta-update.439893.0.html