How can I activate the shipping slot on my WooCommerce store?

The shipping slot is very easy to enable from the plugin settings.

Connect to your WordPress back-office
Go to Plugins > Installed plugins
Search for Cleever payment
Click on Settings
Scroll down and search for the Shipping slot section
Toggle on Enable shipping slot checkbox
Select the shipping method you want the shipping service to fund.
Toggle on or off the Display the associated delivery method checkbox, depending on if you want to also propose this option at normal price to your users.
Add some extra label such as (24h-48h), to provide extra information to your customers
Set the position of this delivery method among others. 1 is the best so that free shipping is proposed first
Click on Save

The Shipping slot enables you to offer a funded free shipping service to your customers.