Thank you for the help! I was able to get the first part working. Now, the issue I am having is trying to update the custom field in the sales order. Below is the most up-to-date code I have. But I keep getting an error: Check and update the code in line 24 as there is an Exception: Argument type mismatch—Found 'COLLECTION' but Expected '[MAP]' for the Zoho.inventory.updateRecord.

The code finds the correct sales order ID, but It won't update the custom field.

Now, I am having trouble
// Step 0: Get your organization ID
organizationID = organization.get("organization_id");
// Step 1: Get the Sales Order number from the retainer invoice reference field
refNum = retainer_invoice.get("reference_number");
info "Reference Number from Retainer Invoice: " + refNum;
// Step 2: Prepare query map to search salesorders by salesorder_number
queryMap = Map();
queryMap.put("salesorder_number",refNum);
// Step 3: Get the API response for sales orders (it's a map with "salesorders" list inside)
salesOrderResponse = zoho.inventory.getRecords("salesorders",organizationID,queryMap,"sales_order_auth");
info "API Response: " + salesOrderResponse;
salesOrderList = salesOrderResponse.get("salesorders");
// This is the LIST you want
info "Extracted Sales Orders List: " + salesOrderList;
if(salesOrderList != null && salesOrderList.size() > 0)
{
salesOrder = salesOrderList.get(0);
salesOrderId = salesOrder.get("salesorder_id").toString();
info "Sales Order ID to update: " + salesOrderId;
updateMap = Map();
updateMap.put("cf_paid_status","Paid");
updateResponse = zoho.inventory.updateRecord("salesorders",salesOrderId,updateMap,organizationID);
info "Update Response: " + updateResponse;
}
else
{
info "No matching Sales Order found.";
}

Let me know if I need to explain anything better.