Shopify loads plugin scripts after everything else on the page. If your store uses a lot of plugins and images it can really slow things down for Slide Cart. You can dramatically speed up Slide Cart by manually pasting the “fast install” code below yourtag.
From the settings page copy the snippet to your clipboard.
Start by navigating to Online Store > Themes > Edit Code
From here open the layout/theme.liquid file and paste the snippet just below your
<body> opening tag. Remember to save your changes.