Plugin: Bookings and configuring for vehicle hire.

-- HikaShop version -- : 6.5.0
-- Joomla version -- : 5.4.6

Hello,

I am using the Bookings plugin and struggling to configure it for a single vehicle hire.

What I have tried:
Advanced Date picker in a custom field on table "Item" and/or "Order".
When "Item" is selected, it displays the date picker and has the Range set to Yes so to and from dates can be picked. It calculates the number of days and displays correctly.
The problem:
The product listing has a price but it does not increase with the number of days selected.

In the plugin settings it has the field to select a custom field for tracking but that is for the "Order" table. The product listing Booking settings is for the table "Item".

I'm totally at a loss as to what I am doing wrong.

How do I configure the settings so selecting two days will double the product price, three days will triple the product price, etc?

Please help!