Examine source code of Opale+

{
  "manifest_version": 2,
  "name": "Opale+",
  "version": "1.0.0.3",
  "description": "Extension pour l'application Opale",
  "icons": {
    "48": "gnucash-icon.svg"
  },
  "web_accessible_resources": [
    "gnucash-icon.svg"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://opale.in.phm.education.gouv.fr/*",
        "https://opale-bas.phm.education.gouv.fr/*",
        "https://opale-bas.in.phm.education.gouv.fr/*",
        "https://opale-bas.hp.in.phm.education.gouv.fr/*",
        "https://opale.in.phm.education.gouv.fr/*"
      ],
      "js": [
        "injector.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{75338ebf-08f9-4b70-a884-ce7016edca30}"
    }
  }
}