Examine source code of Donate Link

{
  "manifest_version": 3,
  "name": "Donate Link",
  "version": "1.0",
  "description": "Shows a heart icon in the address bar when a website accepts donations via the donate link standard.",
  "author": "Web Guy",
  "homepage_url": "https://github.com/webguyio/donate-link",
  "icons": {
    "256": "icon.svg"
  },
  "page_action": {
    "default_icon": "icon.svg",
    "default_title": "Donate"
  },
  "background": {
    "service_worker": "background.js",
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "donate-link@webguyio",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}