Fortnite account on Nintendo Switch

I don't understand your reply

This Microsoft forum is for Xbox and Xbox Games and Apps. You're better off posting your questions for other platforms either directly to the developer Epic Games or on Nintendo's official support forums.

Hi there Jojo, my name is Gerardo and I'm an Xbox player. I'll be happy to help.

Please note that Fortnite packs or items redeemed/purchased through the Microsoft website are for the Xbox console version of the game, not for Nintendo Switch. In this case, in order for the package to appear in Fortnite on your Nintendo Switch, you need to log in with your account on an Xbox console and open the game. This way, the content of the package will synchronize with your game on other platforms, including Nintendo Switch (provided that your Xbox and Epic Games accounts are linked). Please be aware that this policy is directly imposed by Fortnite and not by Xbox; it is a decision made by the Fortnite team.

I appreciate you understanding and if you have further questions please let me know.

Kind regards,
Gerardo.

But not for Fortnite because my friend has a Nintendo Switch and he doesn't need to pay the online subscription to play Fortnite for free.

Yes, when I go into account settings on the website and on her Nintendo switch (through parental controls via Fortnite )the information matches up. However, when I go into Fortnite and I go to settings and to account. The epic account ID and epic display name is different.