使用Composer在PHP项目中加载类

Question

I have difficulties to use this project : https://github.com/php-sepa-xml/php-sepa-xml

I set up everything with composer but I don't know how to generate the xml file.

In the doc folder, there is a sample file, I copy / paste the content in a new php file

<?php
use Digitick\Sepa\TransferFile\Factory\TransferFileFacadeFactory;
use Digitick\Sepa\PaymentInformation;

// Code....
?>

when I run the code I have an error:

Fatal error: Uncaught Error: Class 'Digitick\Sepa\TransferFile\Factory\TransferFileFacadeFactory' not found
 in C:\dev\php-sepa-xml\vendor\digitick\sepa-xml\lib\sample.php:5

I tried to move my php file in different folders and also to change the path but I always have the error.

Note: I'm on Windows so the path may be different.