I'm unable to submit a support ticket for Office 365 because I do not have a license key.  There is a disclaimer:

Do you have your license key ready (only applicable for Nintex 2010 and 2013)?

Please let us know your License key when you submit a support ticket, see Nintex Licensing Information for details on how to do this! (If you are on Nintex for Office 365, please leave the license ID field blank). This will help our team and expediate your submission, without having to get a call from one of our friendly Customer Service Reps .

When you submit without a license key you still receive an error asking for one: