You’ve not provided much information but to sum it up.
AppConfig = remote configuration of the app depending on what controls the app developer provides
Integrating SDK = integrating controls available by your EMM vendor into your App and controlling them remotely
This really depends on use case, your requirements and what you are trying to achieve.
Reach out to your BlackBerry account manager or system integrator. They can show you options on how to integrate the BlackBerry Dynamics SDK into existing apps. For your use case you will most likely end up using https://www.appdome.com/. They are offering an easy way to integrate the BlackBerry Dynamics SDK into existing apps.