Hello,
If the mentioned js file is loaded during 20s total speed won’t be fast.
If you need help with individual site optimization submit request here. Unfortunately, individual site optimization is not included in our basic support because it’s related not just to the theme. Our theme is fully optimized, you can check our demo https://gtmetrix.com/reports/xstore.8theme.com/PWOCFUZp
Good speed result is the combination of good server settings, theme, plugins, optimized images and page content.
Regards