Put the wheels in a freewheel.
If you forget to charge the battery or if there is an electrical fault, you will want to continue and have to push the trolley yourself. By default, the wheels are coupled to the engine, but that is much too heavy. There is an option to run the wheels smoothly and without resistance, separate from the engine.
On the thin shaft, where it is slid over, there are 2 grooves. (1st picture)
When the wheel is coupled to the engine (picture 2) there is no gap.
Press the button on the wheel and slide the wheel back a little. Then it falls into groove 1 (picture 3). You immediately feel that it runs smoothly.