Examine source code of eBay Messages Icon

{
  "manifest_version": 3,
  "name": "eBay Messages Icon",
  "version": "1.0.0",
  "description": "Adds a Messages icon in the eBay header, between the notifications bell and the cart.",
  "browser_specific_settings": {
    "gecko": {
      "id": "ebay-messages-icon@lucas.local",
      "strict_min_version": "115.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "48": "icons/icon.svg",
    "96": "icons/icon.svg"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.ebay.be/*",
        "*://*.ebay.com/*",
        "*://*.ebay.fr/*",
        "*://*.ebay.nl/*",
        "*://*.ebay.de/*",
        "*://*.ebay.co.uk/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_start",
      "all_frames": false
    }
  ]
}