There is no authorization box that comes up. You're connected with localhost which is already allowed.
I would also recommend IB Gateway rather than TWS as it will tell you the status of the connection and will return api outputs to the window and MATLAB. Very good if you wish to troubleshoot API calls.
You can test the IBTWS connection with:
ib.Handle
it should return COM.TWS_TwsCtrl. If it does, it's successfully connected to the ActiveX object.
Refer to https://www.mathworks.com/help/trading/ibtws.html to learn how to use the IBKR trading toolbox.
