Examine source code of API Request Tool

{
  "manifest_version": 2,
  "name": "API Request Tool",
  "version": "1.0.0",
  "description": "Test popular public APIs with one click or send custom GET/POST/PUT/DELETE requests. See status, time, and JSON response.",
  "browser_specific_settings": {
    "gecko": {
      "id": "{303ac962-64ee-4947-b028-192b46c48e21}",
      "strict_min_version": "96.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "browser_action": {
    "default_icon": {
      "16": "images/icon16.png",
      "32": "images/icon32.png",
      "48": "images/icon48.png",
      "96": "images/icon96.png",
      "128": "images/icon128.png"
    },
    "default_title": "API Request Tool",
    "default_popup": "ext/popup.html"
  },
  "icons": {
    "16": "images/icon16.png",
    "32": "images/icon32.png",
    "48": "images/icon48.png",
    "96": "images/icon96.png",
    "128": "images/icon128.png"
  }
}