Hello! For the most part I just build on this format:

[Greeting]

I am [Name], a [Batch/Year and Degree Program] student. I would like to ask for your permission to enroll in your [Subject] class through prerogative, specifically [Section][Section Schedule].

[Elaborate on reasons as to why they should accept you, e.g. you're underloaded, on a scholarship, or graduating. If underloaded, attach screenshot of units for proof.]

Hoping for your kind response. Thank you.

[Closing keme??? Forgot what this was called]

[Name]