My apologies … the Make an API Call module doesn’t return things in exactly the same format as the List Products in a Deal module.
The latter (List Products in a Deal) returns them as separate bundles (one after another), ready for you to use the Array Aggregator to build your own array for Xero.
The former (Make an API Call) returns them in the same way as the raw Pipedrive API call, as an array of Pipedrive products. But you still need to build your own array … so you’ll need to iterate over this array before using the Aggregator.
Add an Iterator before the Array Aggregator. The array parameter should be 23.body.data[].
Your Array Aggregator is now going to have the Iterator as the source module.
Also note - I think you should be using product.code for the Item field rather than product.name, but it depends on how you have the Products set up in Pipedrive.