Automate export invoices to Xero with the correct tax rates / tax codes

[GeminiBlue]

Surely this should be simple! My client sells physical products to customers all over the world. There are three tax scenarios:

1. EU B2C customers (20% tax)

• All orders from EU countries are set to collect 20% tax in settings/taxes
• When exporting orders to CSV: column BI 'Tax 1 Name' = VAT 20%
• Xero needs to record invoice line items with the tax rate = '20% (Vat on Income)'

2. EU B2B customers (no tax)

• We use Exemptify app to let EU customers enter a VAT ID number. If valid, Exemptify correctly sets the taxes on the order to zero. It also creates an entry in the order note and note attribute
• When exporting orders to CSV: column k 'Taxes' = 0, column BI 'Tax 1 Name' = empty, column AT 'Note Attributes' contains a valid tax ID (e.g 'vat-id: BG205101119')
• Xero needs to record invoice line items with the tax rate = 'Zero Rated EC Goods Income'

3. Outside the EU (no tax)

• When exporting orders to CSV: column k 'Taxes' = 0, column BI 'Tax 1 Name' = empty, column AT 'Note Attributes' = empty
• Xero needs to record invoice line items with the tax rate = 'Zero Rated Income'

Every store owner using Xero that sells products to EU countries needs to automate and apply this. How is it usually done? What is the best App?