This achievement can be completed very easily and quickly using Map Creator; I made a compact map that has everything you need for a quick completion.

Link: https://drive.google.com/drive/folders/1EazfZbwYHm2e7V6714XnR1ZJOYYbmFyM?usp=sharing

In order for the map to be selected in the game, you need to transfer the "pesda.cbmap2" file to a folder in this path:
Steam\steamapps\common\SCP CB Multiplayer Reborn\Map Creator\Maps

After that we open the game -> New Game -> Load Map -> Click on Load next to "pesda.cbmap2" -> Select Keter -> Start Game

Now let's move to what you actually have to do. I have mapped out all room locations for you:


You know how to beat the game, so good luck to you in getting the achievement. And yeah, remember that some things depends on randomness.