Apply PHP functions to the website

I have 3 tasks to do.


1° When clicking a button, make a spinner/loader appear when a PDF file is being generated.(The script I'm trying is not running.)
(This task is pure javascript and PHP.)


2° Apply permission for a maximum of 5 downloads of the PDF file (The script I already have).
In another words. One link will be clicked. This link call a php file that generates the PDF file. This PDF file has one ID.
This link will generate the PDF file only a maximum of 5 times for this specific ID.
(This task is pure PHP.)


3° I need to buffer the php file that generates the PDF file with a library. (The Library I already have).
What do you say? are you free at the moment?
I will use this library. If you already applied this Lib in somewhere it ´s great!
https://github.com/phpinnacle/buffer
(This task is 100% PHP.)

If you have experience with those task. If you have already done those kind of taks, let me know.
Thank you for reading.