n8n.io Bookkeeping Workflow Creation for Exact Online -- 3

I'm looking for an experienced freelancer to build an n8n.io workflow that sends sales order entries from 6 sales channels to Exact Online, a cloud-based bookkeeping software, using the n8n package:
https://www.npmjs.com/package/n8n-nodes-exact-online

API integration is already completed for all 6 sales channels. The freelancer's task is to apply the workflow logic to fetch, process, and sync order data to Exact Online.

- Project Requirements
Create a robust and scalable workflow in n8n to fetch and process order data from all sales channels
Send order data to Exact Online in the following structure:
{
"Journal": "fixed value",
"Customer": "fixed value",
"Description": "",
"PaymentCondition": "",
"YourRef": "",
"EntryDate": "",
"PaymentReference": "",
"SalesEntryLines": {
"GLAccount": "fixed value",
"Description": "",
"AmountFC": 0,
"VATCode": ""
}
}

- Handle all relevant order statuses:
Paid
Refunded
Partial Refund
Cancellation

- Implement duplicate entry prevention using order IDs
- Ensure the workflow is efficient, scalable, and maintainable