Examine source code of OnlyMP3 - MP3 Converter

{
  "manifest_version": 3,
  "name": "OnlyMP3 - MP3 Converter",
  "short_name": "OnlyMP3",
  "version": "1.0.1",
  "description": "Send the current YouTube video or a pasted YouTube link to OnlyMP3 for MP3 conversion.",
  "homepage_url": "https://en.onlymp3.cx/",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "64": "icons/icon-64.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "activeTab"
  ],
  "action": {
    "default_area": "navbar",
    "default_title": "Open OnlyMP3 MP3 Converter",
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "64": "icons/icon-64.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "onlymp3@protonmail.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "browsingActivity"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  }
}