Examine source code of URL Host Mover

{
  "browser_specific_settings": {
    "gecko": {
      "id": "{F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4}",
      "strict_min_version": "101.0"
    }
  },
  "manifest_version": 3,
  "name": "URL Host Mover",
  "description": "Multiple groups of URL redirection rules",
  "version": "0.0.0.4",
  "action": {
    "default_icon": {
      "16": "img/um-logo-16.png",
      "24": "img/um-logo-24.png",
      "32": "img/um-logo-32.png"
    },
    "default_title": "URL Host Mover",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "tabs",
    "storage"
  ]
}