I didn’t add the define( ‘SCRIPT_DEBUG’, true ); to the the wp-config file. I just edited the custom.min.js file to only show two rows. And I see now after I waited a while, it worked!
And the buttons are also working. So I think it’s best to edit the custom.min.js file because when it loaded from the custom.js file after I added the code to the wp-config file, the left and right arrows did not work.
Thanks for all your help! 🙂 🙂