Examine source code of export-domain

{
  "manifest_version": 2,
  "name": "export-domain",
  "version": "1.0.0",
  "description": "Copy URL of all tabs of the current site, then close them",
  "browser_specific_settings": {
    "gecko": {
      "id": "export-domain@ffminus",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "clipboardWrite",
    "tabs"
  ],
  "browser_action": {
    "default_title": "Copy URL of all tabs of the current site, then close them"
  },
  "icons": {
    "48": "icons/export-domain-48.png",
    "96": "icons/export-domain-96.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}