These flat-topped millipedes are quite common on well-rotted but dryish wood, such as on the underside of a log on the ground.
In colder weather they remain motionless with their heads pressed to the substrate. This is the best chance of getting a stereo pair, although the one here could be better.
Olympus EM-1 (manual mode), Laowa 25mm f2.8 2.5x-5x ultra-macro at x2.5 andf11 and ISO 400, twin TTL flash hand-held.
The stereo is crosseye.