Examine source code of 99Tools: Web Developer Toolkit

{
  "manifest_version" : 3 ,
  "name" : "99Tools: Web Developer Toolkit",
  "version" : "1.0",
  "author": "99Tools",
  "description" : "Unlock 800+ developer, SEO, and text utilities in one click. The official 99Tools extension for fast, secure, and pro-grade online tools.",
  "browser_specific_settings": {
    "gecko": {
      "id": "extension@99tools.net",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "action" : {
    "default_popup" : "popup.html",
    "default_title" : "Open 99Tools",
    "default_icon" : {
      "16" : "icon16.png",
      "32" : "icon48.png",
      "48" : "icon48.png",
      "128" : "icon.png"
    }
  },
  "icons" : {
    "16" : "icon16.png",
    "48" : "icon48.png",
    "128" : "icon.png"
  },
  "homepage_url" : "https://99tools.net"
}