Airtable items to callin.io Invoice

I'm attempting to build a scenario in callin.io that retrieves a record from Airtable and subsequently generates an invoice in Freeagent.com.

The challenge lies in the fact that the invoice requires multiple line items, which are extracted from Airtable. I'm unsure how to loop through these line items and construct the data structure that the 'invoice items' field in the Freeagent module expects.

My understanding is that I need to iterate and then assemble the JSON structure, but I lack the necessary experience for this task!

Here's my Airtable output bundle and the Freeagent input bundle:

json
[
{
"FreeAgent Ref": "3938630 copy copy",
"Ready to Invoice": true,
"<img alt=":popcorn:" class="emoji" height="20" loading="lazy" src="https://emoji.discourse-cdn.com/twitter/popcorn.png?v=12" title=":popcorn:" width="20"/> CAMPAIGN": [
"receXYbDrSEV6PnyE"
],
"<img alt=":memo:" class="emoji" height="20" loading="lazy" src="https://emoji.discourse-cdn.com/twitter/memo.png?v=12" title=":memo:" width="20"/> INVOICED ITEMS": [
"recmkh4eEjOxeYmsc",
"recDWZvqFOYeJAtiM",
"recjkEKZZf5dPy2og",
"rec1btktbM1BCi1Gz",
"recq32SMQTaLqyzaH",
"recFWM0FsBiT3rWk8"
],
"CLIENT": [
"recGywQ7orhBmGQIi"
],
"CLIENT ID": [
"12121872"
],
"PROJECT ID": [
"3938630"
],
"PO NUMBER": [
"recK5nfoIKika5OiB",
"recK5nfoIKika5OiB",
"recK5nfoIKika5OiB",
"recK5nfoIKika5OiB",
"recK5nfoIKika5OiB",
"recK5nfoIKika5OiB"
],
"Created Date": "2024-09-28T07:29:18.000Z",
"AMOUNT": [
"2926",
"3155",
"11200",
"3500",
"8887",
"13796.2"
],
"ITEM DESCRIPTION": [
"A",
"B",
"C",
"D",
"E",
"F"
],
"PO Fx": [
"POXXX "
],
"id": "recRbBeP0SO9rqb26",
"createdTime": "2024-09-28T07:29:18.000Z"
}
]


And here’s the Freeagent input bundle...

json
[
{
"contact": "12121872",
"project": "3938630",
"currency": "GBP",
"dated_on": "2024-09-28T07:32:18.000Z",
"po_reference": "XXX ",
"invoice_items": [
{
"price": 2926,
"quantity": 1,
"item_type": "Products",
"description": "A"
}
],
"show_project_name": true,
"payment_terms_in_days": 15,
"send_new_invoice_emails": false
}
]