require(vendor/autoload.php): failed to open stream

I know that this issue has been posted many times, but for me it seems to be a different problem. Indeed, this error > Warning: require(vendor/autoload.php): failed to open stream: No such file or directory in C:\xampp\htdocs\site_web\send_mail.php on line 3 > > Fatal error: require(): Failed opening required 'vendor/autoload.php' (include_path='C:\xampp\php\PEAR') in C:\xampp\htdocs\site_web\send_mail.php on line 3 appears at the begining of my code from this line: require 'vendor/autoload.php'; So, I guess there must be a /vendor/autoload.php file somewhere in my computer (I have installed composer and ran `composer require phpmailer/phpmailer`). So, I looked for this file using: `dir /s autoload.php` in the Windows command line, and found one here: `C:\Windows\SysWOW64\vendor\autoload.php`, but for me, **syswow64** folder has nothing to see with **autoload.php**, I don't see what I am missing here.