Examine source code of Focus Shield

{
  "manifest_version": 3,
  "name": "Focus Shield",
  "version": "1.0",
  "description": "Focus Shield helps users maintain concentration by blocking access to specified distracting websites or categories of sites during user-defined \"focus sessions.\" It includes a customizable whitelist for essential sites and a timer to indicate the remaining focus time.",
  "action": {
    "default_popup": "popup.html",
    "default_icon": "focus_shield.png"
  },
  "icons": {
    "128": "focus_shield.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "m6ernestinahandlgscv51@hotmail.com"
    }
  }
}