Ok - there’s several ways you can do this.
The simplest is to create a 2nd endpoint - create_destination or similar that you’ll use to process every individual item on the list.
Set it up something like this:
The endpoint
The new Workflow
The original workflow
Then call this endpoint for every item on the list by adding this in the original workflow:
Whilst this is the easiest, it’s not necessarily the most performant - you need to space out your calls that endpoint to avoid jamming it, 5 seconds is good practice. If you need to go fast then you can look at recursive workflows, or use the dedicated Bulk endpoint.