If you need an invoice for the purchased Sync license, you need to register, if you haven't yet, and login to License Management Account. To register use the CustomerID from Purchase Confirmation e-mail that is sent to you right after license purchase. All password resetting mails will be sent to e-mail address associated with the purchase.
See here for more details about registering and using the Console.
Once you login, form a dropdown menu select "Invoice" option. Update the billing address as necessary and download the invoice.
License Management Account also gives option to automatically send the invoice for monthly subscription renewals to the e-mail.
If the invoice doesn't seem right for a reason, please write to support, mention what exactly is not correct and submit the following additional details:
- Company name and billing address. For individuals, person's name shall be communicated.
- VAT ID, or Tax ID. Explicitly mention if VAT shall not be charged and mentioned in invoice.
- The sum for which invoice shall be issued. This might be the purchase itself, or license update (additional seats purchased), or license renewal.