The Tatuus cars released by S397 are used for F3. The Tatuus MSV F3-016 is used in the International F3 (for example BRDC British F3) and the Tatuus F.3 T318 is used for various regional F3 championships (for example the W-Series, or F3 Asia).
The only F3 2019 mod, as far as i know, is this WIP one https://forum.studio-397.com/index.php?threads/smmg-f3-2019-wip-beta.61665/