Hey ho :)
Go straight to the three posters, keep left, adjust your view to see the light, then jump onto it and walk along the wall. The enemy patrols from the ramp to the left, around the corner to the right, and back. It’s visible in the editor but invisible in the EXE, so try to stay right until you pass the ramp.
If you fall from the map, you’ll need to restart the EXE, as there’s no respawn yet, sorry for the inconvenience! (If you fall from the ramp at the very top, it’s possible to continue but much harder. I recommend going left first, then right. I know it’s dark, but if you follow one of these paths (max. 3 paths), the light at the end will help you see.)
Hope this helps, and thanks for trying the game! - and sorry for the invisible enemy, I'm trying to fix it.