uninstall.php

<?php
if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly
}

// if uninstall not called from WordPress exit
if ( ! defined( 'WP_UNINSTALL_PLUGIN' ) ) {
    exit();
}

/*
 * Only remove ALL product and page data if WC_REMOVE_ALL_DATA constant is set to true in user's
 * wp-config.php. This is to prevent data loss when deleting the plugin from the backend
 * and to ensure only the site owner can perform this action.
 */
if ( defined( 'WC_REMOVE_ALL_DATA' ) && true === WC_REMOVE_ALL_DATA ) {
	// remove created folder
	$upload_dir = wp_upload_dir(); 
	$pdf_path = $upload_dir['basedir'] . '/woocommerce-store-catalog-pdf-download';

	if ( is_dir( $pdf_path ) ) {
		$files = glob( $pdf_path . '/*' );

		// remove each file
		foreach( $files as $file ) {
			if ( is_file( $file ) ) {
				@unlink( $file );
			}
		}

		// remove the directory
		@rmdir( $pdf_path );
	}
}