The asset doesn’t need any setup by you to function. By default there are no leaderboards in the save. The save will automatically create itself when you first create a leaderboard with the system. The leaderboard save goes to the users computer persistent datapath, under the /Leaderboard directory. For more on this please and to get the location for your system, please see the Unity documentation: Application.persistentDataPath
TextMeshPro Support
The asset has an extra package that adds a version of the leaderboard display that uses a TextMeshPro text component instead of the normal unity component. This version is not in the package as standard in-case more beginner users get are unsure of the difference or don’t have TextMeshPro setup. The import the package, just navigate to Carter Games/Leaderboard Manager/TMP and double click the package and press import. Once the editor has reloaded you’ll have the Leaderboard Display (TextMeshPro) script to attach in to objects and use just like the normal display script.