Toyota GR series of engine, is a V6 engine with variance of 1GR-FE (3,955cc), 2GR-FE (3,456cc), 3GR-FE (2,994cc) and 4GR-FE (2,499cc), actually there are 5GR and 6GR variance which you may find more info on their model under
https://en.wikipedia.org/wiki/Toyota_GR_engine.
Normally, when thinking of a rocker cover gasket, a complete kit may have a main rocker cover gasket, plug seal, rocker cover bush, moon seal, which is depend on the rocker cover design, but this GR series type of rocker cover, there are 2 special o-ring found inside the rocker cover, which some may overlook it.
Can you see the "8" shape o-ring and the "O" shape o-ring in this rocker cover?