Fortnite location is not recognized?

I rebuilt my PC and had to reinstall the epic games launcher. This wants to completely reinstall fortnite, although the data is still on my pc.

Have already tried the installation folder where the data are hinzutun but it does not help

Do you know what I have to do?

I think when you set it up, it may have overwritten some of the Fortnite data. You should just reinstall (Fortnite)