You need to choose the cache plugin that has that option, for example, WPRocket, W3 total cache etc.
We don’t have option to defer JS in our theme, it’s cache plugin option.
Besides this point has good results http://prntscr.com/uiw0w1
At the same time your page it very large and images take 4.4Mb http://prntscr.com/uiw1zf
We would recommend you to optimize images using special tools, for example https://tinypng.com/
It will help you to reduce the page size and speed up the page loading.
