Nuxt 2 PWA Caching Issue

pwa {
workbox: {
    cacheOptions: {
      cacheId: '<npm package name> || nuxt',
      directoryIndex: '/_nuxt/',
      revision: undefined
    },
    cleanupOutdatedCaches: true,
    runtimeCaching: [
      {
        urlPattern: '/^\/API_.*/',
        strategyOptions: {
          cacheName: 'api-cache',
        },
      }
    ]
  },
}