1. Go to this page and download the library: Download ssheduardo/redsys-laravel library. Choose the download type require.
2. Extract the ZIP file and open the index.php.
3. Add this code to the index.php.
<?php
require_once('vendor/autoload.php');
/* Start to develop here. Best regards https://php-download.com/ */
$key = config('redsys.key');
$parameters = Redsys::getMerchantParameters($request->input('Ds_MerchantParameters'));
$DsResponse = $parameters["Ds_Response"];
$DsResponse += 0;
if (Redsys::check($key, $request->input()) && $DsResponse <= 99) {
// lo que quieras que haya si es positiva la confirmación de redsys
} else {
//lo que quieras que haga si no es positivo
}