Help on Saving and Loading game

Hey! I’m working on a game in Construct 3 where you have a world map with several levels that can be completed in any order. What I want is: when the player finishes a level, the game should save that progress (for example: level 1 completed, level 3 completed, etc.), and when the app is opened again on Android or iOS, it should automatically load that progress.

Could someone explain the best method or share a simple example of how to handle a save system for non-linear levels? Basically:

• Marking a level as completed
• Saving it on the device
• Loading it when the game starts
• Ensuring it works on both Android and iOS

Any guidance, advice, or quick tutorial would be super appreciated. Thanks! 🙏