Examine source code of Substack Exporter

{
  "manifest_version": 3,
  "name": "Substack Exporter",
  "description": "Export Substack posts, comments, notes and subscriptions as Markdown, CSV, HTML or EPUB",
  "version": "0.0.1",
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "96": "icon/96.png",
    "128": "icon/128.png"
  },
  "permissions": [
    "cookies",
    "notifications",
    "alarms",
    "idle"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "author": "rxliuli",
  "action": {
    "default_icon": {
      "16": "icon/16.png",
      "32": "icon/32.png",
      "48": "icon/48.png",
      "96": "icon/96.png",
      "128": "icon/128.png"
    }
  },
  "homepage_url": "https://rxliuli.com/project/substack-exporter",
  "browser_specific_settings": {
    "gecko": {
      "id": "substack-exporter@rxliuli.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "open_in_tab": true,
    "page": "options.html"
  }
}