Hi Mate

Yes you can 'withdraw' from Bittrex and use the Bitcoin Address given when you go to Buy the Software.

This will send the funds to Margin Software for your license.

You create the API in the settings on Bittrex.

Once payment is made you then need to fill in the web form that loads with the First Half of your Secret from the API in the correct Line for your Exchange.

To use the DEMO you cannot use it on your Exchange account.

On the drop down menu select the DEMO ones listed.

Hope this helps.

TheWood