Create S3 upload script for nodejs

I need a simple JS script s3url.js that I will be able to call
under Windows using nodeJS like this:

node s3url.js

This script will create an AJAX call to the PHP functions
depicted in s4reduced.php.
These function generate signed URLs for upload and download
files from and into AWS S3.

The goal is to write the functions that upload and download
the given string into S3 and test that it works inside of the script
s3url.js called from node.js.
I included a schematic view of how the script should look like.

For this matter you will need to create some PHP script returning
the result of the URL generating functions and some functions in JS
to call these PHP functions.
The PHP functions need to stay the same, unmodified, the work in browser.
I need to write a script that will work also in node.js.

I need this to be tested in your AWS account before you give me the script.
I only change the access keys and it should work in my account. In that case
I will pay the invoice.
Attached is the file S3.docx (for uploading to the system) which is a .zip file containing the files s3reduced.php and s3url.js
CAUTION - the attached file is a DOCX but in reality it is a ZIP. You need to rename it. PPH somehow does not accept ZIPs.