I've contacted EA help about this for switching from Xbox to PS4. Apparently it's a known issue that you can't switch persona and they don't know when it will be fixed. So you have to wait for the full game.
in order to see the new platform, you need to create the club first in the game. Depending on platform, that might not be possible yet.
In order for it to show up in the web app now, you need to have created a club on the new platform in Fifa 18 before August 1. If that wasn't the case, then you'll need to wait.
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