For more info, check out this PlayStation 5 4K Resolution Guide Rocket League will output at 4K at 60 FPS with HDR if Enable 120 Hz Output is set to Off.

HDR is disabled in Rocket League when 120 Hz is enabled.

Go to Settings from the PlayStation 5 Home Screen.

To change your Video Quality Settings on your PlayStation 5:

120 FPS support also requires the appropriate video settings on your console.

To play at 120 FPS, compatible hardware (HDMI 2.1-capable 4K/120 Hz display, HDMI 2.1 cable) is required.

Fixed a bug preventing 120 FPS support on the PS5.We’ll share more details once we’re closer to voice chat making a siiick comeback next year. We are on track to bring voice chat back to the game in early 2022. Earlier this summer, we said that we are working on bringing an improved, more comprehensive voice chat system to Rocket League.We’re also aware that some players experience performance issues when using in-game voice chat - some sort of mid-match lag or service disruption - and we do not want voice chat to hinder quality of play. As many of our players know, the current voice chat system is not up to modern standards, making it difficult to use in a fast-paced game environment. We are temporarily removing voice chat with v2.04.

Rocket League Steamworks Fix Update