Examine source code of Gmail Refresh

{
  "manifest_version": 2,
  "name": "Gmail Refresh",
  "version": "1.2",
  "description": "Aggiorna automaticamente tutti gli account Gmail collegati con un solo click",
  "browser_specific_settings": {
    "gecko": {
      "id": "giuseppe@vedda.it",
      "strict_min_version": "102.0"
    }
  },
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "activeTab",
    "https://mail.google.com/*",
    "tabs",
    "notifications"
  ],
  "browser_action": {
    "default_icon": {
      "48": "icons/icon-disabled-48.png",
      "96": "icons/icon-disabled-96.png"
    },
    "default_title": "Gmail Refresh (apri Gmail per attivare)"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "developer": {
    "name": "Giuseppe Vedda",
    "url": "https://vedda.it"
  }
}