change smtp env to server env

.env.example

@@ -5,8 +5,8 @@ REDIS_URL="redis://localhost:6379"
 
 NEXTAUTH_URL="http://localhost:3000"
 
-NEXT_PUBLIC_SMTP_HOST=smtp.mailtrap.io  # Example SMTP host
-NEXT_PUBLIC_SMTP_USER=[email protected]  # Example SMTP user
+SMTP_HOST=smtp.mailtrap.io  # Example SMTP host
+SMTP_USER=[email protected]  # Example SMTP user
 
 
 AWS_DEFAULT_REGION="us-east-1"