Samsung kicked off the Android 10-based One UI 2.0 beta program for the Galaxy Note9 last month and now it's seeding the stable build of Android 10 for its 2018 flagship. However, the update, sporting version number N960FXXU4DSLB, is currently only rolling to those who participated in the beta program and weighs just 100MB. If you are enrolled in the beta program, you can download the stable build on your Note9 by heading to the Settings > Software update menu. Those of you who didn't participate in the beta program and are running Android Pie should expect the Android 10 update...
Source: https://www.gsmarena.com/samsung_galaxy_note9_android_10_update-news-40791.php