When the Xero integration is enabled in Preno, Preno will generate an invoice for you once the booking is checked out.
Create booking in Preno.
Add deposit/payments to the booking.
Check out the booking in Preno.
Final invoice for the booking is generated in Xero.
When the final Xero invoice is generated, the deposit and the payments will automatically be reconciled to the invoice in Preno.
The only thing left for you to do is to reconcile the payments to the corresponding bank statement lines.