The requirement to access your BitaBIZ Outlook add-in, is that you must click your "inbox" in Outlook and have an email active in the reading pane:
If your BitaBIZ Outlook add-in does not appear when you are in your inbox...
Then it is because you have disabled "Reading Pane" in your Outlook.
In this case, you gain access by opening an e-mail in your inbox.
Or by enabling "Reading Pane" as shown in the image below.
Click: View > Reading Pane > select "Right" or "Bottom":