Black Ops 4 is not cross-platform.

Unfortunately, Crossplay is not currently supported on Black Ops 4.

There is no official way to play Call of Duty with a PC and Xbox, but some people have reported that they have been able to do so by using a third-party program.

There is no definitive answer, but it seems unlikely.

Yes, Black Ops 5 is cross-platform.

Back 4 Blood is not crossplay compatible.

Black Ops III is cross-platform.

To add a friend on Black Ops 4, you’ll first need to open the game and go to the main menu. From here, you’ll want to select “Settings” and then “Friends.” Here, you’ll be able to add friends by entering their Gamertag or PSN ID.

There are a few ways to add Xbox friends on PC. One way is to use the Xbox Live app on your computer. Another way is to use the Xbox app on your phone and connect it to your computer.

There is no direct answer to this question, as the Xbox One and PlayStation 4 are different platforms with different capabilities. However, it is possible to play Call of Duty on either platform, as long as the game is compatible with both systems.