Samsung started rolling out the update to Android 10 with One UI 2.0 on top to the Galaxy S9 in late January, and today this has reached those units sold by Verizon in the US.
The update will arrive over-the-air in the next few days, as it’s likely to be undergoing a staged rollout. After installation, you’ll be running Android 10 with Samsung’s brand new One UI 2.0 on top, and you’ll also have the February 2020 security patch level, which is still the most up-to-date there is. Your new software version after installation will be QP1A.190711.020.G960USQU7DTA8.
If your phone hasn’t yet notified you about this update, and you’re the impatient type, then it can’t hurt to manually check from time to time by going to Settings > System updates > Check for system updates. You’ll need to be on Wi-Fi.