Fix ReferenceError

✅ Solution

The "ReferenceError: window is not defined" error usually occurs because `window` is a browser-specific object and your code is running in a server-side environment (like Next.js SSR, Node.js) where it doesn't exist. To fix this, conditionally use browser-specific code only when running in the browser, commonly achieved using a check like `typeof window !== 'undefined'` before accessing `window` or by lazy-loading the supabase-auth client within a `useEffect` hook in React/Next.js. If using Next.js, consider using dynamic imports with `ssr: false`.