Changed env in README.md

README.md

@@ -179,7 +179,7 @@ Let's deploy the Next.js application to [Vercel](https://vercel.com). If you've
 
 1. Create a new project on Vercel, select the `apps/nextjs` folder as the root directory. Vercel's zero-config system should handle all configurations for you.
 
-2. Add your `DATABASE_URL` environment variable.
+2. Add your `POSTGRES_URL` environment variable.
 
 3. Done! Your app should successfully deploy. Assign your domain and use that instead of `localhost` for the `url` in the Expo app so that your Expo app can communicate with your backend when you are not in development.