[Konstantinos]

pawn Код:

AddCheckpointToRace(1, 0, 2378.034423, -1256.948120, 23.392478);
    CreateRace(1,"TestRace", 50, 0,0,0,1);
    
    AddCheckpointToRace(2, 0, 0, 0, 0);
    CreateRace(2,"Race Farm", 50, 0,0,0,1);

The first raceid should be 0 instead of 1.

Moreover, you will need to know the races exist because if MAX_RACES is let's say 50, it will create 48 3D labels at 0.0 coordinates.