Examine source code of EventCopy for Calendars

{
  "manifest_version": 3,
  "name": "EventCopy for Calendars",
  "version": "0.0.1",
  "description": "Do you post your events to multiple calendar sites? This extension makes it easy — scrape your event details from any event page with one click, then fill out submission forms on other calendar sites automatically. Works with Luma, Eventbrite, and any site that uses standard event formats.",
  "permissions": [
    "storage",
    "activeTab",
    "scripting",
    "downloads",
    "tabs"
  ],
  "action": {
    "default_icon": {
      "48": "icon.png",
      "128": "icon.png"
    },
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "all_frames": true
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "eventcopy-for-calendars@pro.tools",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "48": "icon.png",
    "128": "icon.png"
  }
}