Save Currency

So lately I’ve been trying to save coins as currency everytime a button is being tapped. I am able to get it to work, but once I close the app and go back on the coins goes back to 0. Is there a way I can save it when I go back on and when I close out of the app? I’m going to have multiple scenes where it requires to show how much coins you have.

https://coronalabs.com/blog/2013/12/10/tutorial-howtosavescores/

https://coronalabs.com/blog/2016/09/21/introducing-new-preference-storage-features/

https://coronalabs.com/blog/2014/10/14/tutorial-saving-and-loading-lua-tables-with-json/

https://coronalabs.com/blog/2013/12/10/tutorial-howtosavescores/

https://coronalabs.com/blog/2016/09/21/introducing-new-preference-storage-features/

https://coronalabs.com/blog/2014/10/14/tutorial-saving-and-loading-lua-tables-with-json/