Hi @Erum Mirza,
Bruce answer is helpful. We can implement this feature in asp.net core(recommended, asp.net not recommended).
Asp.net core signalr provides real-time communication capabilities based on WebSockets. If the number of users is very large, we can consider migrating to Azure SignalR, which is very simple and requires only one line of code.
And we also have some related service like Notification Hubs. If you have any other questions, please let me know.
Best Regards
Jason