Hi lisipat ,
First of all, welcome to the Buttonizer Community!
Thank you for opening the console log and showing the errors, this points us directly to the right direction! 🙂
It seems that there's an error in the API endpoint the dashboard connects to. Could you check the errorlog from your webserver and try to find if there are any visible PHP errors related to the following URL:
Or errors with the exact plugin file path:
Let me know!