Examine source code of Auto Dark Mode is

{
  "manifest_version": 2,
  "name": "Auto Dark Mode",
  "version": "1.0",
  "description": "Automatically switches between dark and light mode based on time.",
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icons/icon.png"
  },
  "permissions": [
    "storage",
    "theme"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{baf8fac1-d2db-4ad9-aa00-6c8697e9489d}"
    }
  }
}