This should work:
FIRST go to ‘backend workflows’ and create an API workflow that accepts a value of the type ‘User’.
This workflow creates a new thing of type ‘Basket’ using the information in the ‘User’ value provided to it. Finally use ‘return data from API’ to return the resulting ‘Basket’ thing that this backend api workflow just created.
Now every time you call this backend API workflow from your regular workflow, it will create and return a new ‘Basket’.
THEN try this in your workflow:
Add an action called ‘Schedule API workflow on a list of things’, provide the list of users you need to generate 'Basket’s from, select the API workflow that you just created above and it will do the needful.