There’s nothing stopping me from using my phone’s battery in my toys. The same way nothing stopped me from connecting a small toy electric motor to a straight up power connector to plug into a wall socket when I was a kid.
All you need to do is connect the red and black wires from the battery to the leads on the device. Now, it might cause the thing to break/melt/catch on fire, but that’s not the fault of the battery. 🤷🏻♂️ 🤣