I have entered the code on the web at xbox and I have no xbox just a switch and I still have not received the skin but when the order is complete what is to be done
The seller shows "Completed" because he gave you the code.
You are responsible for the rest.
To redeem the code, you need to connect an XBOX account to your Fortnite account.
To get the skin in the end, you have to play with the XBOX and redeem the code, even if it's only for a short time.
Because I don't have an xbox
Then unfortunately it is not possible to redeem the skin.
I 'm sorry! Maybe some tutorial will show you how to do it anyway.
However, it is not possible in the legally legal way.
All the best and have fun!