CORS settings error

Hi,

On my personal some features from the wordpress template I purchased are not working. The developpers replied:
"There's CORS errors on your page and likely why it's not working.
Could you contact your webhost and ask them on this. This can be corrected by CORS settings in your host.
They should be familiar with checking and correcting this as it's part of hosting settings."
How can I make those corrections ?
Thx for help.