Canadian Secretary to the King
The Canadian secretary to the king (French: Secrétaire canadien du Roi) is the senior operational member of the royal household for the monarch of Canada, presently King Charles III. The office was established as Canadian secretary to the queen in 1959. The present office holder is Donald Booth, who was appointed to the position in 2019.
Source: Wikipedia — Canadian Secretary to the King (CC BY-SA 4.0)