Add B2 (S3 compatible) functionality to video aggreation PHP Script Website

I need someone who has experience working with PHP scripts as I need someone to modify a script to store all existing and new images in Backblaze B2 (s3-like API available). The website is a video aggregation site, but we store copies of all of the video thumbnails. They are currently stored on the server but we need them in b2 as the site continues to expand. The script also contains built in scrapers that scrape other sites for the videos, so when it imports new videos it needs to store those thumbnails in b2 as well. You'll have to modify a significant amount of the site to make this work

I have a staging site that you will make all your changes on first, and then once approved I'll provide access to the production server to make the changes there. I can provide access to the staging site so you can look at the code, please just let me know if you need this.

The PHP script we are using is AVS8.1.