Examine source code of KTabSwitcher

{
  "manifest_version": 3,
  "name": "KTabSwitcher",
  "version": "1.1",
  "description": "Search open tabs easily.",
  "permissions": [
    "tabs",
    "activeTab",
    "scripting"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "commands": {
    "toggle-popup": {
      "suggested_key": {
        "default": "Ctrl+Shift+E",
        "mac": "Command+Shift+E"
      },
      "description": "Toggle popup"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "ktabswitcher@yourname.dev",
      "strict_min_version": "109.0"
    }
  }
}