Write IT-Documentation for a company PHP + JQuery + Microsoft project

Hello,

For an IT project, we need to write documentation.

Check this intro video of the portal:
https://drive.google.com/file/d/12-IGIxrybAzjK1d-gykezgkxR2F3NoxE/view?usp=sharing

What you need to know is the following:
Go through the file main_prod.inc and document every possible action (as in the screenshot shown).

Check the main_prod.inc file.

There you have to cover all these questions:
1. Where is the data coming from?
2. What is the flow when the user clicks the button (or makes the action)
3. What AJAX requests are triggered then?

I am looking for freelancers who have experience in documenting IT projects.
Also, please show me the documentation that you have written as a reference.

Thanks and looking forward to working with you