Trying To Call SendFax() Returns EtherFaxResult "Invalid Or Missing File"

Hey There,

I am using EtherFax C# library to send Fax and as specified in your document (https://docs.etherfax.net/docs/send-fax) creating a FaxSend object and calling SendFax() method like below

`var fax = new FaxSend()
{
DialNumber = "8565551234",
FaxImage = imageBytes // byte[] of image retrieved from other process
};

// begin sending the fax
var result = client.SendFax(fax);`

But am getting InvalidOrMissingNumber enum value for EtherFaxResult which per documentation should be InProgress.

Any idea (Or) suggestion?