After installing MOKIT you'll see setup instructions. Click on "Start setup".

Enable Widget

This step will add required files to your themes folder, which will be used in your cart page.

Enable MOKIT Rate Provider

This will use MOKIT as rate provider during checkout, before you can enable this be sure that your shop has enabled Shopify Rate Provider API.

MOKIT Plugin

After these steps you'll see the active plugin on your cart page.