Vonage Desktop App: Sending Faxes Sign into the Desktop App. Click My Apps and then click Fax (left sidebar). Click the + New Fax button and if more than one fax line, select the line to use. Enter the phone number to receive the fax in the TO field, then click the NEXT button. Mark Use Cover Page option, if you want to add one: Accept default cover page or select a cover page for use from the menu. Complete required fields for the cover page you selected. Upload the fax you want to send. You can either drag and drop into the Attachment window or click Attach File. Click PREVIEW to review and then click SEND.NOTE: If unsuccessful, the system automatically makes up to five attempts to resend.