On the loading screen, we can see a character staring at the monitors. On the screen in the center, you can see the PD packet, hidden behind the memorable purple cube from the fifth season.
The purple cube statue is located in the southwestern part of the Dusting Chimneys, i.e. the location on the northeastern edge of the map. This is where you must go. The location is marked on the map below:
When you are in the right place, XP will appear above the ground, just behind the cube. Interact with the package to complete the challenge.
XP will not appear in the aforementioned place if you have not yet unlocked the Birth of Chaos loading screen and you have not completed the corresponding missions of the current week.