Examine source code of Night Field & Fireflies

{
  "manifest_version": 3,
  "name": "Night Field & Fireflies",
  "version": "1.0.0",
  "description": "A calm night field with fireflies that rise from the grass when you hover.",
  "permissions": [
    "tabs",
    "topSites"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "fireflies@techsparrow.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "icons": {
    "16": "assets/icon16.png",
    "32": "assets/icon32.png",
    "48": "assets/icon48.png",
    "128": "assets/icon128.png"
  },
  "action": {
    "default_icon": {
      "16": "assets/icon16.png",
      "32": "assets/icon32.png",
      "48": "assets/icon48.png",
      "128": "assets/icon128.png"
    },
    "default_title": "Night Field & Fireflies"
  },
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  }
}