Remind them in Canada, the King is the Head of State; so, in order to become citizens, all applicants for citizenship who are 14 years of age or older **must** swear or affirm to be faithful and bear true allegiance to His Majesty King Charles III, King of Canada, His Heirs and Successors.
If the candidate does not take the Oath, they cannot be presented with the Oath or Affirmation of Citizenship form to sign or their certificate and do not become a Canadian citizen.