No motor activity on Waveshare Jetracer

HI i constitute the jetrecer and setting up the Waveshare Jetracer, I tried running the Basic Motion file (basic_motion.ipynb) in Juypter Notebooks. Step 1 & 2 executed perfectly with steering working. When down to the step to run the motors, I get no motor movement. Tried everything I can find but no help. My program in Seven Racer belongs to GitHub - waveshare/jetracer: An autonomous AI racecar using NVIDIA Jetson Nano.