On many of our ebikes the button for switching lights on and off (front and rear) is on the boardcomputer, you can recognize this button by the lightbulb 💡 icon.
Is there no lightbulb 💡 icon on the boardcomputer? Then you can switch the lighting on and off by pressing the + button on the left handle for 5 sec.
On our citybikes Gazelle Esprit you can find a switch to turn on the lights on the front and rear light of the bike. With these switches you can turn on the lights individually.
Enjoy the light!