Composer not auto-loading required classes - php

Question

I'm new to Composer and I'm really struggling to auto-load my classes with composer. What am I missing in the following process?
I installed the package in my PHP includes folder (which is outside the document root - I'm not sure if that matters) like this:
composer require monolog\monolog
It stated it completed successfully and I confirmed the project was added to my vendor folder.
My entire composer.json file looks like this:
{
"require": {
"monolog/monolog": "^1.22"
}
}
My entire test file looks like this:
<?php
require_once "vendor/autoload.php";
use Monolog\Logger;
$log = new Logger("name");
?>
And I get this error when I load the page:
Fatal error: Uncaught Error: Class 'Monolog\Logger' not found in C:\Dropbox\Projects\Web\Websites\Instamation\wwwroot\qbtest.php:6 Stack trace: #0 {main} thrown in C:\Dropbox\Projects\Web\Websites\Instamation\wwwroot\qbtest.php on line 6
It includes the vendor/autoload.php file without any error.
I've tried to run these commands in composer without any change:
composer update
composer dump-autoload -0
I've also tried it with different packages and I get the same error, so I'm pretty sure it has nothing to do with the monolog package.
Is there a step here I'm missing? I don't need to manually define which classes to autoload in a json file if I require them in composer, do I?
Edit 1:
As requested, here's the paths to my different files.
Path to the test page:
C:\Dropbox\Projects\Web\Websites\Instamation\wwwroot\qbtest.php
Path to the composer.json file (outside the document root but in my includes path):
C:\Dropbox\Projects\Web\Websites\Instamation\wwwincludes\composer.json
My vendor folder is here:
C:\Dropbox\Projects\Web\Websites\Instamation\wwwincludes\vendor\
And inside my vendor folder I have these folders and file:
bin/
composer/
monolog/
psr/
autoload.php

Answer 1

You need to include autoload in your qbtest.php as following:
require_once "../wwwincludes/vendor/autoload.php";
use Monolog\Logger;
$log = new Logger("name");