Need two different VAT lines when a surcharge is generated on a customer

Summary:

Some customers need to generate an surcharge at the AR invoice. But the standard surcharge that can be configured at the Customer setup doesn't work because the ERP shows a single line with both VAT.

When an invoice with a % surcharge is presented to the Spanish tax agency, the two VATs associated with the invoice must be presented (the base VAT and the surcharge separately), not one with the total amount. How do I configure this so that two lines are displayed?

Content (please ensure you mask any confidential information):

As both VATS must be presented as two different VATS, we tried applying them manually to the invoice line, but when we apply to different VATS for the same line, we received this error: