If you would like to change your in-game name, you can do so by changing your platform name.
Keep in mind that Psyonix Support is not able to manually change or modify platform names. If you have difficulties with changing your platform name, please contact your platform directly.
Follow the steps below to get started:
Your email must be verified before you can change your display name. For more info, check out How Do I Verify My Email Address?
For more info, check out: How to Change Your Epic Games Display Name.
For more info, check out: How to Change Your PlayStation Network Online ID.
For more info, check out: How to Change Your Xbox Gamertag.
For more info, check out: SteamID, Steam Account Names, Merging Accounts and Deleting Accounts.
For more info, check out: How to Adjust Nintendo Account Profile (Country, Email, etc.)