During the main quest “To Catch a Coon” in South Park the Fractured But Whole, you receive a riddle from Conner called the “Death Store” riddle.
Over the phone you are told: “A place where death comes in shapes and sizes. Go into this store to find what your prize is”. The problem is that there’s no more waypoints in this mission.
The solution: It’s the gun store in the north-west of South Park. The name on the map is Jimbo’s Guns. See the screenshot below:
Go there on foot (fast travel is disabled in this quest), enter the store and take a selfie with the guy in the blue shirt. This solves the riddle and advances the quest and triggers the “Happiness Reigns” Riddle.