To join a party via code, click the icon between 'Invite to Party' and '+ Add Friends'. As with any Call of Duty game, you can tailor your profile via the Customisation menu in the Career tab to show ...

To change your display name in Black Ops 6, tap on the Settings cog icon in the main menu. Select the second to last option, Account & Network. Tap the Activision Account box then Change Display Name ...