Reset the Monimoto device by connecting it to USB charger or Laptop/PC. If you have a new device, simply hold the small button next to the SIM card for 3 seconds.
If you have an iPhone, please go to your iPhone's Bluetooth settings, click on your Monimoto device and choose 'Forget the device' (if there was a paired device).
Finally, go to Monimoto app - create a new account by providing your phone number and entering the confirmation code. Then pair Monimoto with your phone like you did during the first setup.