Examine source code of Rentamap

{
  "manifest_version": 3,
  "name": "Rentamap",
  "version": "0.1.6",
  "description": "Rentamap gives you future rental information about the house you want to buy.",
  "author": "Rentamap",
  "action": {
    "default_icon": "icon-96.png",
    "default_title": "Rentamap",
    "default_popup": "index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "extension@rentamap.fr",
      "strict_min_version": "130.0"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.guy-hoquet.com/achat-vente/**",
        "*://*.seloger.com/annonces/achat/**"
      ],
      "js": [
        "content.bundle.js"
      ]
    }
  ],
  "icons": {
    "48": "icon-48.png",
    "96": "icon-96.png"
  },
  "web_accessible_resources": [],
  "permissions": [
    "activeTab"
  ]
}