function mySystem() { 
const prefersDark = window.matchMedia('(prefers-color-scheme: dark)');toggleDarkTheme(prefersDark.matches);prefersDark.addListener((mediaQuery) => toggleDarkTheme(mediaQuery.matches));function toggleDarkTheme(shouldAdd) { document.body.classList.toggle('drK', shouldAdd);}}

Want to use local.storage i tried a lot but idid not getting how to use local.storage here.