website broken link and 404 error checker

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 3,
  "version": "1.1.1",
  "name": "__MSG_appName__",
  "description": "__MSG_appDesc__",
  "default_locale": "en",
  "permissions": [
    "tabs"
  ],
  "host_permissions": [],
  "icons": {
    "128": "icon/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/chunk-vendors.js",
        "js/content.js"
      ],
      "css": [
        "css/main.css"
      ],
      "run_at": "document_start"
    }
  ],
  "background": {
    "service_worker": "js/background.js",
    "type": "module"
  },
  "action": {
    "default_icon": "icon/icon128.png",
    "default_title": "popup",
    "default_popup": "popup.html"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "img/*",
        "icon/*"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'; frame-src 'self'; child-src 'self'"
  }
}