What’s the difference between a Xero invoice and a Pay Now button?

What’s the difference between a Xero invoice and a Pay Now button?

The Xero integration adds buttons to the invoices, but they aren’t exactly the same as the Pay Now buttons.

Having a Pay Now button on an invoice is therefore different/separate from the Xero integration, and unfortunately will not work automatically with the Xero integration. See 'Why are the transactions not showing in Xero?' for more information on this.