Tax type when creating Xero invoice

I am trying to override the tax type when creating a Xero invoice. I have followed the suggested link (https://developer.xero.com/documentation/api/accounting/types/#tax-rates) and have tried setting the tax type to INPUT as would be suggested by the API documentation, however this does not override in Xero once the invoice is created.
It appears to not set "Invoices 0 LineItems 0 TaxType" to INPUT as required
What am I doing wrong here?

Hey @katalystjay

As we can check, the input key has already been set to the invoice and the API seems to respond correctly according to Xero's documentation -