How to clear and recreate arduino object

I’m doing the mobile rover, part of the engineering kit, I’m following the chapters provided on Ardiono website for this kit. I recieve this message

>> a = arduino('COM5', 'MKR1000', 'Libraries', 'MotorCarrier');
carrier = addon(a,'MotorCarrier');
No add-on library uploaded to the board. Clear and recreate the current arduino object to include the appropriate library.
For a list of available libraries, type 'listArduinoLibraries'.

I’m not sure how to clear and recreate the object.
Thanks.

>> a = arduino('COM5', 'MKR1000', 'Libraries', 'MotorCarrier');
carrier = addon(a,'MotorCarrier');
No add-on library uploaded to the board. Clear and recreate the current arduino object to include the appropriate library.
For a list of available libraries, type 'listArduinoLibraries'.

addon is a function that is missing. Either You need to write the code for it, or include a library containiing addon.

Always post the entire code so we don't need to spend time on guessing.

Not sure what you mean, that is the whole code, unless you mean this :

>> listArduinoLibraries

ans =

  12×1 cell array

    {'Adafruit/BNO055'       }
    {'Adafruit/MotorShieldV2'}
    {'CAN'                   }
    {'I2C'                   }
    {'MKRMotorCarrier'       }
    {'MotorCarrier'          }
    {'RotaryEncoder'         }
    {'SPI'                   }
    {'Serial'                }
    {'Servo'                 }
    {'ShiftRegister'         }
    {'Ultrasonic'            }

I'm brand new at this so I don't understand the reason for any of the error messages.

The first posting is an error mesaage.
What is the second post showing? Nothing I understand nor recognize.

That is the list of available libraries.

I did not ask for that. I asked for the Your code.