Examine source code of KeepSecure

{
  "manifest_version": 3,
  "name": "KeepSecure",
  "version": "1.0.2",
  "description": "Secure password manager with local sync.",
  "permissions": [
    "tabs",
    "activeTab",
    "storage",
    "scripting"
  ],
  "host_permissions": [
    "https://127.0.0.1/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_script.js"
      ],
      "all_frames": true
    }
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": "images/favicon.ico"
  },
  "icons": {
    "128": "images/favicon.ico"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "keepsecure-spahol@gmail.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}