update

wp-content/plugins/youtube-feed-pro/vendor/smashballoon/customizer/bootstrap.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace SmashBalloon\YoutubeFeed\Vendor;
+
+use Smashballoon\Customizer\Container;
+use Smashballoon\Customizer\Tabs\Manager;
+\define('SBCVER', 2.0);
+if (!\defined('CUSTOMIZER_ABSPATH')) {
+    \define('CUSTOMIZER_ABSPATH', \trailingslashit(__DIR__));
+}
+if (!\defined('CUSTOMIZER_PLUGIN_URL')) {
+    \define('CUSTOMIZER_PLUGIN_URL', \plugin_dir_url(__FILE__));
+}
+//initialize container
+$container = Container::getInstance();
+//Setting tabs manager singleton
+$container->set(Manager::class, Manager::getInstance());
+//Load .env variables
+if (\class_exists('SmashBalloon\\YoutubeFeed\\Vendor\\Dotenv\\Dotenv')) {
+    $dotenv = Dotenv\Dotenv::createImmutable(__DIR__);
+    if (\is_file(__DIR__ . '/.env')) {
+        $dotenv->safeLoad();
+    }
+}