B this letter I am attesting that I'm responsible
How To Write Attestation Letter For Admission?
Here is what I have found for you online www.siguniversity.org/letter-of-attestation Besides, if you need the help with more than just a letter, but with the admission essay, I want to make you sure that Prime Writings site would be the best choice.
Here is an example https://admissionsandutme.com/2019/10/12/what-is-an-attestation-letter-used-for-university-admissions/. Take a look here on how to write a scholarship essay as well.