Activation Keys - Use one activation for six individual workbooks

I Have 6 individual excel workbooks that I want to distribute and protect with an Activation Key but if I protect them all I have to use 6 different activation keys for each excel workbook. Is there a way or can you add/update XLS Padlock to use one activation key for multiple workbooks? Or a way to do it now with XLS Padlock 1.3.2?

You can use the same activation key if you set the same “Application Master Key” for all of your workbooks