Hello,
In general, our theme is already optimized and doesn’t have too many resources to make your website slow. Most likely, your website performance suffers from the content you have added to your website. It may happen in case of too many plugins, large not optimized images, or other resources. So we suggest you remove unnecessary plugins, install some kind of JS & CSS optimizing plugins like WP Rocket. You can find our guide about how to optimize your website built with our themes here https://xtemos.com/wordpress-performance-optimization-the-ultimate-guide-in-2021/
Kind Regards