Examine source code of Arquivo.pt

{
  "manifest_version": 3,
  "name": "Arquivo.pt",
  "version": "1.1.0",
  "permissions": [
    "contextMenus",
    "activeTab",
    "scripting"
  ],
  "background": {
    "scripts": [
      "page.js"
    ],
    "persistent": false
  },
  "icons": {
    "16": "./img/16.png",
    "48": "./img/48.png",
    "128": "./img/128.png"
  },
  "action": {
    "default_icon": "./img/128.png",
    "default_popup": "popup.html",
    "default_title": "Arquivo.pt"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{051ff8b2-afce-4234-920f-f65dec8c4da7}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}