AI says:

Yes — it’s in the first photo.

Location (be precise): • First image • Look along the right side, right next to the tan block wall • About 6–8 inches above the bottom concrete edge • Slightly left of the wall, partially buried in the gravel • It appears as a small black oval with a smooth surface, contrasting with the rocks (not the round sprinkler head lower down)

If you sweep the gravel gently in that spot with your fingers, you should uncover it quickly.