sahilmankar/NotificationService ? reverse-engineered prompt

Build me a simple .NET Core web API for sending notifications by email and SMS.

I want an app where I can send a message to a user, choose whether it goes by Gmail or text message, and customize the subject and body. It should be easy to plug into other apps for alerts, reminders, or basic notifications.

Please set up clean endpoints, request models, and the service logic so it’s straightforward to send both kinds of messages. Use configuration from app settings for anything sensitive, and keep the code easy to read and extend. If you need to check current docs online for the best way to wire things up, go ahead.