LG released the Android 10 update for the G8 ThinQ in South Korea last November, and last month, it was rolled out for the units locked to Sprint and Verizon's networks in the US. Now, the rollout has expanded to the unlocked units of the G8 ThinQ in the States.
The update carries version number G820QM20a and weighs around 1.9GB in size. A complete changelog of the release is currently unavailable, but the users who have received the update report it comes with the January 2020 Android security patch and new UI.
The Android 10 update is rolling out over the air and it will be a few weeks before it reaches all the G8 ThinQ units. If you can't wait for that update prompt to pop-up on your device, you can try checking it manually by heading to your phone's Settings menu.