Communicating with IDTech Devices requires the following framework/libraries to be imported into the project:

IDTech.framework
ExternalAccessory.framework
MediaPlayer.framework
AVFoundation.framework
AudioToolbox.framework
CFNetwork.framework

Also, import the following resource bundle:

IDTech.bundle

Under Build Phases, select Link Binary With Libraries and click the Add (+) button

On the Choose Frameworks screen, click "Add Other" in the lower left

Navigate to the IDTech.framework folder, and click "Open"

Link the ExternalAccessory framework. On the Choose Frameworks screen, type "exter" into the search bar, select ExternalAccesssory.framework and click "Open"

Repeat process for MediaPlayer.framework, AVFoundation.framework, AudioToolbox.framework, and CFNetwork.framework

Link another library. Under Copy Bundle, click the Add (+) button, click "Add Other", navigate to and select the IDTech.bundle file and click "Open"

The Build Phases should now include the required frameworks/libraries for the BTPay 200