https://wccftech.com/rocket-league-is-getting-120fps-options-on-xbox-series-sx-later-this-year/

Rocket League, the still popular sports/racing game created by Psyonix, has received official details on its next-gen console enhancements. The developers said the game is already equipped to work on PlayStation 5 and Xbox Series S|X through backward compatibility, enjoying 'significantly faster load times' and 'improved split-screen performance' on these new consoles.

Later this year, though, Xbox Series S and X will get a 'Performance mode' option that can run Rocket League at 120 frames per second. The Xbox Series X will target 2688x1512 resolution in this mode, while the Series S is going to target 1344x756, both of which are 70% of 4K and 1080p, respectively. Notably, there's no such info for the PS5 version of the game, though that doesn't mean it won't happen in the future.