Here are some links provided by the professor.

https://www.apa.org/advocacy/guide/letter-email (Links to an external site.)

https://www.ncsl.org/portals/1/Documents/SampleLetterToYourSenator.pdf (Links to an external site.)

https://www.senate.gov/senators/senators-contact.htm

And I also attached the lecture PowerPoint which is related to this writing in the files.