After finding Remnant cores at various Kett locations on the map, SAM will give you a location for a Remnant installation.
When you enter, there is a Glyph locked container. Here's the guide on where the 4 Glyphs are and how to solve the Decryption Puzzle to open the container.
Glyphs 1 & 2
Both are in the entrance hall, before you go through the gray corridor.
Glyph 1: Is at the top of the entrance hall, where the container and the console are.
Glyph 2: Is on one of the pillars of the round void entrance.
Glyph 1
Glyph 2
Glyphs 3
Go through the corridor to the next room.
Glyph 3: Is on one of the pillars
Glyph 4: At the end of this room at the wall.
Glyph 3
Container
Now you can solve the Decryption Riddle at the Container.