Many samples and examples of such cover letter templates can be searched for on this website for your needs and requirements. (sampletemplates.org)
In this page, you will find two samples of such cover letters that are written asking for reference. (bestcoverletters.com)
Likewise, you may initially have a policy with no additional cover for disability due to illness or accidents, but later in life you may feel the need for such a cover. (indianexpress.com)