Godot World Map Level Generation issue


Issue to implement a New Super Mario Bros U world map

Hi everyone. I’m pretty new to Godot and I’m currently implementing a world map by following this tutorial by GameDev Knight : World Map Level Generation
The problem is, despite the fact that everything is working as intended, I can’t figure out how to unlock 2 or 3 levels in the same time after beating one level.

Can someone help please ?