Write an application to the headmaster of your school requesting him to issue you a studying certificate?

Subject: Request for Studying Certificate

Dear Headmaster,

I am writing to kindly request a studying certificate for my academic records. I require this certificate for [mention reason, such as university application or job application]. I would be grateful if you could issue this certificate at your earliest convenience.

Thank you for your attention to this matter.

Sincerely, [Your Name]