Examine source code of Tab Numbers

{
  "manifest_version": 3,
  "name": "Tab Numbers",
  "version": "1.1.0",
  "description": "Displays [1]-[8] in tab titles for easy Ctrl+Number keyboard navigation",
  "permissions": [
    "tabs",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "firefox-tab-numbers@piyushjain",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}