Wolfenstein Youngblood: Souvenir from Dunwall Location Guide
This achievement / trophy is located on Victory Boulevard (north side). Usually you unlock this place through the normal course of the story. You must also unlock the “Dieselkraftwerk” weapon, which is on the main mission mission “Brother 2“.
Use the express train in the metro to get to Victory Boulevard (north side). In the video below you can see the building you have to enter, go upstairs and open the door with the Dieselkraftwerk weapon. Inside you will find a shrine with the memory of a “Dishonered Rune!”
The code for the red chest in this small room is 2161.