[EDIT] You get them every 4th SHD level during the event.
I thought it was by just levelling up that you would get one alongside a regular apparel cache key but it's not.
Just did Grand Washington Hotel on challenging with 5 directives as part of a 4 man MM group, levelled up and got a regular cache key.
Looked around in game and don't see any info on it, what am I missing?


