Letter Has Completed Community Service I Need To Write A Community Service Letter?

I need to Write a community Service letter? - letter has completed community service

I am a supervisor at a pharmacy, and students in high school and recently permormed 20 hours of volunteer service to the pharmacy. How can I write a letter to the school or to declare that they have completed the20 hours, I have it look official and a student said. Thestudents dried, and the platform, management and medication.