Examine source code of Open Multiple Addresses

{
  "manifest_version": 3,
  "name": "Open Multiple Addresses",
  "version": "1.4.0",
  "description": "Open multiple addresses at once",
  "icons": {
    "48": "img/icon.svg",
    "96": "img/icon.svg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "webext-open-multiple@andreaswagner.org",
      "strict_min_version": "109.0"
    }
  },
  "action": {
    "default_area": "navbar",
    "default_icon": "img/toolbar-icon.svg",
    "default_popup": "popup.html",
    "default_title": "Open multiple addresses"
  },
  "permissions": [
    "clipboardRead",
    "tabs"
  ],
  "commands": {
    "_execute_action": {
      "suggested_key": {
        "default": "Alt+T"
      }
    }
  }
}