Examine source code of Reading River

{
  "manifest_version": 3,
  "name": "Reading River",
  "version": "0.1.1",
  "description": "Save articles from Firefox into Reading River.",
  "action": {
    "default_popup": "popup.html",
    "default_title": "Reading River"
  },
  "permissions": [
    "storage",
    "activeTab",
    "scripting"
  ],
  "host_permissions": [
    "https://petercurry.org/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "reading-river-firefox@example.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}