A template is the shape of an article, not the article itself. Authors pick a template and then fill its fields.
What you maintain
Open Form Templates at /app/knowledgebase/form-templates. Add the fields the article should capture. Permissions control who can view, create, edit, or delete a template.
On the article, choose the category and the template before completing the template fields. Templates belong to the service desk library. Trust Centre articles are a different library.