Fortbyte Challenge 24 has the hint “Found in Fatal Fields” and can be collected in the main building in Fatal Fields. Go up the stairs to the first floor and enter the second door on the right.
All Fortbyte Locations 1-100 (Fortnite)
Fortbyte #2 | Loading Screen 6 Fortbyte Location (Fortbyte #2 Location)
Fortbyte #3 | Using Skull Trooper Emoji at the western most point (Season 9 Fortbyte Locations)