There will be a small magnet, and a sensor with a wire leading to the controller. It detects how many times the pedal crank goes around, so it will be somewhere in that area.
Google "pedelec sensor", but there are many types. You might have a torque-sensing crank, which would be mentioned somewhere in the advertising copy. This is a completely different sensor.
After googling your bike, which was necessary because you FAILED TO PROVIDE a link or a picture, I could tell you which type of sensor you have, but since you made me do extra work to try and help YOU solve YOUR problem, I am not going to, you can search for both types while reflecting on your error.