Examine source code of Dictionary Lookup v4

{
  "manifest_version": 2,
  "name": "Dictionary Lookup",
  "version": "1.0",
  "description": "Quickly look up word definitions using the Free Dictionary API.",
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon.png"
    }
  },
  "permissions": [
    "activeTab",
    "https://api.dictionaryapi.dev/"
  ],
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{52e2703e-b827-4cf9-93b5-99d760fd1e86}"
    }
  }
}