Get Tax Invoice for Guest

Does anyone know how I can get a tax invoice from this site for a guest that stayed in my place ? 

Lindsey Lee 28 days ago

I'm having same issue.  Kept getting request from customer service (multiple messages for same booking on the same day) to provide guest with invoice but after I've attached the invoice (both .doc and .pdf) and press the sent button - nothing went through.  

I tried to contact guest via their booking messages but only get error messages.