Hi there,
Unfortunately, the credentials given in the secure note is not working and we can not access to the dashboard of your WordPress installation. Therefore I will give you common issues list which I suggest that you follow:
In addition please make sure that the PHP memory limit is enough to operate the website and the theme. To change the PHP memory limit please kindly read the article below:
https://theme.co/apex/forum/t/troubleshooting-customizer/196 (Not Working or Showing a White Screen section.)
You may need to contact your hosting service provider for some of the steps mentioned above.
Thank you.