Need Help With Levels

Hello,
So basically I am creating a level based game and using checkpoints for that. I need the game to start from last played level/scene when the user starts the game. How do I do that ?
regards

 

instead of start use start checkpoint and restart checkpoint

 

I am trying but not working.

 

Make sure your scenes are aligned. You need to align them every time you add new scenes and test.

 

I want when game start, it will star from last level i played. I tried many way but its not working.

If i set start checkpoint in start button its don't work.

How can i? Can you help me?