Examine source code of Contacomes Netra

{
  "manifest_version": 2,
  "name": "ContacomesNetra",
  "version": "1.4",
  "description": "Acceso a Contacomes Netra",
  "applications": {
    "gecko": {
      "strict_min_version": "57.0",
      "id": "contacomesnetra@example.org"
    }
  },
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "browser_action": {
    "default_title": "Contacomes Netra",
    "default_icon": "icon.png",
    "default_popup": "enlace.html"
  },
  "permissions": [
    "https://netra.contacomes.org/"
  ]
}