Diagnosis
The scooter is in "zero start" mode. It requires a kick-push to 3 mph before the motor engages. This is a default safety setting.
How to Fix It
Change it to "kick start" mode. Power the scooter on. Press and hold the Mode button and the Power button simultaneously for 5 seconds. You will hear two beeps. Now give it a kick-push to start.
If That Didn't Work
The brake lever micro-switch might be stuck, telling the controller the brake is applied. Squeeze and release the brake levers several times. Listen for a faint click.
Heads Up
Always start with the scooter pointed in a safe direction. "Kick start" mode can cause a slight jerk when it engages.