MSAF Type B

Hey, so I have a upcoming midterm that is worth 30% and become of some personal reasons and mental-health reasons I don't think I'll be able to write it. I submitted my first and only administrative MSAF last semester and they didn't require any documentation, so I was wondering if I would need any documentation this time as it is my second overall, but my first this semester? Also, if documentation would be required or just to safe, how would I go about providing documentation for some personal reasons affecting my mental health? Thank you so much in advance.