Multiplayer loading screen

I’m setting up a multiplayer game when a players connect to the host they are put into a lobby. Once the host starts the game I want to display a loading screen that shows the progression bar in the loading screen of each player connected.

I will be using servertravel once the lobby owner starts the game. My issue is I’m not sure of the information i need to grab from the clients to pass to the server showing progression or even how to grab it. Once I figure that out I can pass it to the server to then update the loading screen widget.

Any help to point me in the right Direction will help!