CHF - AP01 – Appointment of Director
Companies House Form AP01 is used to appoint an individual as a company director. The appointment must be registered with Companies House within 14 days of their appointment.
Companies House indicate that this form should be filed online except if you are restoring a company to the register or are a societas Europaea (SE).
This online form can therefore be found here on the Companies House website: https://www.gov.uk/government/publications/appoint-a-director-ap01.