How to compress mp3 file in php

I am doing a php project. In my project, I need to compress mp3 files to reduce the file size because I need to store a lot of mp3 files.

How can I compress it in php? I am using laravel framework. If possible, I want it without extra installation. I already checked ffmpeg, but I was not able to use it due to the poor documentation. How can I achieve it?