Examine source code of Catastro a Google Maps

{
  "manifest_version": 3,
  "name": "Catastro a Google Maps",
  "version": "1.0",
  "description": "Convierte coordenadas del Catastro español a Google Maps. Click derecho → menu con opciones",
  "browser_specific_settings": {
    "gecko": {
      "id": "{a0b1c2d3-e4f5-6789-abcd-ef0123456789}",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "assets/icon-16x16.png",
      "48": "assets/icon-48x48.png"
    }
  },
  "icons": {
    "16": "assets/icon-16x16.png",
    "48": "assets/icon-48x48.png",
    "128": "assets/icon-128x128.png"
  },
  "permissions": [
    "activeTab",
    "contextMenus"
  ],
  "host_permissions": [
    "*://www1.sedecatastro.gob.es/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://www1.sedecatastro.gob.es/Cartografia/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}