parents living and working abroad

Hi, I was applying to student finance for the first time and I'm confused on some things.

- in my application I told that my parents are living and working abroad while I am living in the UK. looking online for students in my scenario before I saw that my parents have to fill in something called the PFF2 form to submit their financial details. my first question is that are they 100% supposed to submit a PFF2 form?

- my second question is if they are done with the PFF2 form where and how are they supposed to submit the PFF2? they cant make a student finance account online.

-my third question is that my fathers pay slips contain sensitive information about his organization. are there alternative documents that he can submit as evidence for household income on the PFF2. neither my mother or I work by the way.