Examine source code of Freediumify

{
  "manifest_version": 3,
  "name": "URL Replacer",
  "version": "1.0",
  "description": "Replaces part of a URL with user input.",
  "permissions": [
    "activeTab",
    "scripting"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.jpg",
      "48": "icons/icon48.jpg",
      "128": "icons/icon128.jpg"
    }
  },
  "icons": {
    "16": "icons/icon16.jpg",
    "48": "icons/icon48.jpg",
    "128": "icons/icon128.jpg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "susu@freediumify",
      "data_collection_permissions": {
        "required": [
          "browsingActivity"
        ]
      }
    },
    "gecko_android": {}
  }
}