The carrier today released Android 9 Pie update for LG V35, coming in as version V350AWM20b. The 20b update is sized about 1.46GB and is already rolling out as an OTA. Besides Pie, the update also installs May security patches.
If you are rocking an LG V35 at AT&T, check for the Pie update now. Hit up Settings > scroll down and tap System > tap AT&T Software updates. Now, tap Check for updates. If an update is already available for your device, it will give you on-screen prompts to help you download and install the update.
Once the update is installed, verify it under Settings > About phone > Software version. For Android 9 Pie, the version has to be V350AWM20b. If it’s not that, then this means you have more updates available. Check for an update again.