Yeah, everything is possible. Just need to research as well. From my experience there are several libraries already created you just need to add the library to Bagisto and the rest will work the same as well. Just try the below one also,
This is something that you are customizing and you should be familiar with the basics. If you want some customization you can contact Webkul for support.
This is updated on the by the event triggered. So the event which is triggered will git this controller i.e. packages/Webkul/Velocity/src/Http/Controllers/Shop/ShopController.php. In this controller, you will see the method named getItemsCount. You need to update here.
From this, I am assuming that you have knowledge of Laravel and code changes because this is some kind of customization. But changing in Bagisto will also impact the updates as well.
Just go to Bagisto root directories and run the command which the package has given after successful installation.
Just follow the documentation and check the sales package in the directory i.e. packages/Webkul/Sales.