Warning: require(vendor/autoload.php): Failed to open stream: No such file or directory in C:\www\plugin\PHPMailer\get_oauth_token.php on line 18

Fatal error: Uncaught Error: Failed opening required 'vendor/autoload.php' (include_path='C:\xampp\php\PEAR') in C:\www\plugin\PHPMailer\get_oauth_token.php:18 Stack trace: #0 {main} thrown in C:\www\plugin\PHPMailer\get_oauth_token.php on line 18