PHP error calling a function from a package - php

Question

I am new to php and have just installed my first package via composer. I'm now trying to call a function from the package I installed as follows:
<?php
require_once 'vendor/autoload.php';
$value = 1;
$aws = AmazonGiftCode::make()->buyGiftCard($value);
echo $aws;
?>
But I get the following error:
PHP Fatal error: Uncaught Error: Class 'AmazonGiftCode' not found in
/public_html/php/test.php:4 Stack trace:
#0 {main} thrown in /public_html/php/test.php on line 4
Based on my (albeit limited) experience with other languages, I'm guessing I have to load the package that contains the class first. The package folder is in the same directory as the test.php file, in the subfolder vendor/kamerk22/AmazonGiftCode/. But I think this is where I don't know enough to troubleshoot it based on the information I could find.

Answer 1

Your directory structure should look like this.
test.php
composer.json
vendor
└───autoload.php
└───kamerk22
└───AmazonGiftCode
Make sure you installed the package using composer, and not by downloading it.
I'm guessing I have to load the package that contains the class first.
Unlike what you would normally expect when importing stuff, when using composer you only have to import the autoload.php file, and composer will take care of loading other packages as needed. By as needed what I mean is that as soon as composer sees you use the AmazonGiftCode class it will import the AmazonGiftCode package, but if one of your REST endpoints doesn't use anything from the AmazonGiftCode package it won't ever load it. This allows you to not have to worry about slowing down the entire application when you want to use a composer package for only a few endpoints. At least that's the way I understand how composer works.

Answer 2

Just run composer dump-autoload once and the class should known then.
You could also get verbose and use kamerk22\AmazonGiftCode\AmazonGiftCode;
But that AmazonGiftCode looks quite Laravel specific... that's why it may still fail, even if it may be found by auto-load. One needs to setup Laravel framework in the first place; just see this query (just in case if you may wonder where all these missing classes may come from).