Examine source code of dkPassword

{
  "manifest_version": 2,
  "name": "Password Manager by Digitalkey.eu",
  "version": "1.5",
  "description": "Store passwords securely for websites.",
  "permissions": [
    "storage",
    "activeTab",
    "tabs",
    "scripting",
    "nativeMessaging",
    "clipboardWrite",
    "<all_urls>",
    "*://*/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>",
        "https://*/*",
        "http://*/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "dkpassword@digitalkey.eu"
    }
  }
}