Call of Duty: Warzone
How do I play with a friend that is on a different platform?
Players on PlayStation 4, Xbox One, Steam, and Nintendo Switch can randomly matchmake with or against each other in all Online Match types.
To enable Cross-Platform Play (it is enabled by default):
- In the Main Menu
- Select Options
- Select the Gameplay tab
- Check the Cross-Platform Play box
Source: Rocket League