Ecobike S3 - How to Adjust the Saddle Height to Suit the Rider; Precautions Required Prior to each Use

Then, use the pin.
3.3. How to adjust the saddle height to suit the rider.
3.4. Precautions required prior to each use
Verify that the brakes and the front & rear lights are all working properly. Also,
check the pressure of the tires.
On derailleur geared bicycles the rear derailleur automatically tensions the
chain.