To receive data from marker, you need to get it inside Update method.
IMPORTANT! Do not receive markers inside AdvanceTick, because markers lifetime are limited by current frame.
public class UserInputReceiveSystem : ISystem, IUpdate {
...
void IUpdate.Update(in float deltaTime) {
if (this.world.GetMarker(out WorldClick markerClick) == true) {
...
}
}
}