Workbox PWA 完美，除了离线页面捕获

如何解决Workbox PWA 完美，除了离线页面捕获

这是 Service Worker 模板，它可以正常工作，直到取消注释捕获行。如果有人能够使此配置正常工作，请发布答案，谢谢！

const FALLBACK_HTML_URL = '/offline.html';

if (typeof importScripts === 'function') {
  importScripts('https://storage.googleapis.com/workBox-cdn/releases/5.0.0/workBox-sw.js');
  /* global workBox */
  if (workBox) {
    console.log('WorkBox is loaded');
    workBox.core.skipwaiting();

    /* injection point for manifest files.  */
    workBox.precaching.precacheAndRoute(self.__WB_MANIFEST);

    /* custom cache rules */
    workBox.routing
      .registerRoute(
        new workBox.routing.NavigationRoute(
          new workBox.strategies.NetworkFirst({
            cacheName: 'PRODUCTION'
          })
        )
      )
      //// !!! [if uncommented error]   .catch(() => caches.match(FALLBAK_HTML_URL));
  } else {
    console.log('WorkBox Could not be loaded. No Offline support');
  }
}