Usage patterns
〈人・動物〉が伏せをするto lie down (as an exercise or trained response)
「伏せ!」と命令するto give the command 'down!'
The trainer commanded the dog, 'Down!'
〈人〉に伏せを教えるto teach (a dog) to lie down
I'm teaching the puppy to lie down.
伏せの姿勢をとるto assume the lying-down position
The soldier took a prone position to avoid the enemy's attack.