Hello,
If you check your own providing URL of the GTmatrix, This is clearly showing in the attached screenshot that the Speed of the site is slow because of the Images has not been optimized and Compressed and because of JS and CSS has not been Minified and because of the Server as well: https://ibb.co/99V8vym
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 Better WordPress Minify and a caching plugin like WP Super Cache. Also, you can use GTmetrix tool to see what makes your website slow and optimize these parts of your website.
Best Regards.
.
