I'm building an app where I've been doing all of the design layout on the default Main.storyboard. I'm attempting to create something that utilizes Apple Pay, and the guidance from Apple is that I need to use the PassKit PKPaymentButton for that. However, I can't seem to figure out how I can add that to the Toolbox so that I can use it from within the storyboard. I have been able to successfully create it programatically from within my ViewController, but I'd like to be able to use the designer. Does anyone know if it's possible to add PassKit components to the Toolbox - and if so, how?