We recommend you install Slim with Composer. Navigate into your project’s root directory and execute the bash command shown below. This command downloads the Slim Framework and its third-party dependencies into your project’s vendor/ directory.
composer require slim/slim:3.* Require the Composer autoloader into your PHP script, and you are ready to start using Slim.
<?php require 'vendor/autoload.php'; Don’t have Composer? It’s easy to install by following the instructions on their download page.