All non-regulated course certificates (Leadership, Personal Development and Safety) can be downloaded from your British Canoeing (or other National Association) membership portal.
All you need to do is find the award in your qualifications or credentials section, double click on it and a download button should appear which allows you to download a copy.
If you wish to have a duplicate regulated qualification certificate (Coaching Courses) then these must be requested through British Canoeing Awarding Body here.