How to pass data from a client to the Dedicated server during login?

I have a map in the game default map from which the user connects to the lobby in the game server(dedicated). I want the user to pass the menu selection data to the server during login to the server. How can I pass these data from client side to server? In the lobby gamemode I have functionalities thata ccepts these values from the users and take them to appropriate maps.

Try to use sessions and custom tags.

There are multiple ways. Check out this blog post.