Hello,
I am not sure to understand your question. To be able to download your invoices in pdf format, you need to install the dompdf library. Once it is done, a pdf icon will appear next to each invoice to download them.

Let me refer to our documentation:

Installing DomPDF library (for creating PDF for invoices):

Download the file dompdf.zip from My Downloads
Unzip the file. You should obtain a folder called /dompdf
Copy that file into /components/com_invoices/helpers/ folder
The resultant folder should be /components/com_invoices/helpers/dompdf/
Make sure you are running PHP 5 or greater (otherwise DomDPF will not run)
Make sure your PHP directive MAGIC QUOTES is set to OFF (otherwise DomPDF may encounter problems)
Create a new folder in the root of your Joomla installation, and name it "pdfinvoices". This is necessary in order to be able to attach PDF invoices when you send email invoices.


You can find the whole article here: http://www.joomlathat.com/documentation/invoice-manager/installation

Thanks very kind , another courtesy , where you change the VAT that then I view the invoice ?
I set address name etc but close the tax code and not one I get my VAT
Thank you

Hello,
to define a VAT you need to go to the Taxes section in the administrator, and there, you can define the default ones you want. Once created, you will be able to apply them for each invoice you create within the Items tab of the invoice.

However, the "codice fiscale" you are showing in the attachment is a static information displayed such as the invoicer name or the invoicer address.
When creating an invoice, you can define it in the Invoicer tab. The english field is called "Invoicer fiscal num."

Please, tell me if this solves your question,
Joan