通过网站安装Python模块

Question

I recently have a website running a python script. Unfortunately, this python script requires another python module but I do not know how to install it on the website. How do you install a python module for a website. Below is my code

PHP:

<?php

$VAR = 'test';
$output = shell_exec('python test.py ' . $VAR);
//$output = shell_exec('python -m pip install requests'); <-- tried that but does not work.

echo $output;
?>

Python Code:

import requests

response = requests.get('google.com')
print (response.text)

I do not get anything when I go to my php page, but if I hastag import requests and response and print and just put "print ("Hi")" it works. Any ideas on how to install requests?

Is there anyway I can get a shell for a website?

NOTE: I AM USING CPANEL.