During the oath ceremony, you will see an IRCC agent in private who will identify you with your IDs, will have you chop up your PR card. During that process, they will check with you your home address because they will mail the citizenship certificate to that address. Also, after the ceremony you will need to sign the Oath or Affirmation form and send it back by email. If it's anything like our ceremony, after the oath taking itself, they will show you a powerpoint presentation to explain how to sign and return that form. During that presentation, they will instruct you to also include your home address in the body of the email. I guess it's a way for them to double check your address.
So no. You don't need to apply separately to get your citizenship certificate.