Examine source code of REST API Client Tester

{
  "manifest_version": 3,
  "name": "API Client",
  "author": "onyxwizard",
  "version": "1.0",
  "description": "A Postman‑like API client that works on Firefox desktop & Android",
  "permissions": [
    "tabs"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "action": {
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png"
    },
    "default_title": "API Client"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "api-request-client@onyxwizard.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "websiteContent"
        ],
        "optional": []
      }
    }
  }
}