Binding Library - setting a const value for an API Key

I'm binding a native iOS framework that requires an API Key to be set as a const.

In their sample ObjC app, it looks like this

const unsigned char ApplicationKey[] = {0x81, 0x67, ... };

When I build, I get an error

"Error MT5210: Native linking failed, undefined symbol: _ApplicationKey. Please verify that all the necessary frameworks have been referenced and native libraries are properly linked in. (MT5210)"

When making a binding, I'm unclear on how I should model this? I'm open to either just hardcoding it in the binding, or (better) being able to pass it in as a parameter from my app.