Examine source code of ArtTab

{
  "manifest_version": 3,
  "name": "ArtTab",
  "version": "1.22",
  "description": "View dynamic digital art every time you open a new tab.",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "permissions": [
    "storage"
  ],
  "host_permissions": [
    "https://arttab.xyz/*"
  ],
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'"
  },
  "action": {
    "default_icon": {
      "16": "icon16.png",
      "48": "icon48.png",
      "128": "icon128.png"
    }
  },
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "arttab@arttab.xyz",
      "strict_min_version": "109.0"
    }
  }
}