Edit the int.random to be set by the user and issue with corner radius

I am just getting started with Swift and I would like the user to be able to set the range of the Int.random for example : if he want to have a random number in the range of 0 to 100, he can set it here.

The view of the settings:

Basically it should change my function numberGenerator, at the moment the default range is 0 ... 10000 but I want it to adapt when the user want to change it.

My code at this moment:

And I have another issue, when I change the cornerRadius of the labelNumber it doesn't show any difference like the generateButton.

The result when I run the app at this moment: