Fax cover sheets are included by default when faxing. You can disable the cover sheet from Settings ('gear' icon) > Organization > check the box for Suppress Default Fax Cover Sheet > Save Changes.
If you need to make updates to your fax cover sheet, please reach out to support@kno2.com with the desired changes.
Optional: You are welcome to include a copy of your existing cover sheet with markups or you may refer to this sample template to make markups: