https://www.gamespot.com/articles/fortnite-week-7-gnomes-guide-retail-row-treasure-m/1100-6457985/

A new set of Fortnite challenges means a new batch of optional objectives to complete in Battle Royale, provided you own the Battle Pass. Week 7 challenges include two in particular that will require either some legwork on your part or a guide to specific locations--which is where we come in.