Netgear Mobile - won't let me enter a different username

I have an AirCard815S.

 

I changed the admin username from the default for security reasons.

 

Now I want to use the Netgear Mobile app. I have iOS 11.3.0.

 

However, the app username is set at admin.  I can't change it. When I select it my only options are to copy or share it.

 

Since change from the default admin name should be basic security, I can't understand why it is hard coded into the app and unchangeable.

 

Any assistance greatly appreciated.