https://www.gamespot.com/articles/week-4-fortnite-challenges-ice-cream-truck-locatio/1100-6457429/

Season 3 of Fortnite: Battle Royale is winding down, but it's not too late to still complete its Battle Pass challenges. Fortnite's Week 4 challenges posed to be tricky, but with the help of a map, its main hassle--tracking down ice cream trucks--isn't all that tough..

The full list of challenges is outlined below; one requires you getting the right weapon and utilizing it efficiently (dealing a specific amount of damage with a sniper rifle), while another has you tracking down chests in the Flush Factory or supply drops around the map. There are two in particular that you might need some help with.