In order to run the app on your device, make sure you create a LocalConfiguration.xcconfig file in this folder and add your own bundle id, team id and signing preference. Its structure is the same as the CustomConfiguration.xcconfig file, but, obviously skip the #include directive.
This file will not be committed to the repository (it's in the .gitignore), but will be included by XCode and it will update the information automatically. Also, because we're using this local config structure, don't make changes to the build settings regarding the bundle id, team id or signing preference. If you did so, just delete the custom values and let the build settings be updated from the xcconfig files.
If you want to use the dev API, copy the Development link that's commented in the CustomConfiguration.xcconfig and use it in your own LocalConfiguration.xcconfig. If you want to test production, don't add an API_URL variable at all.
This might seem obvious, but don't make any changes directly into CustomConfiguration.xcconfig, because they'll be committed with the rest of the changes. Use LocalConfiguration.xcconfig for your own configs.
If you're interested in how this works, check out this tutorial
This project uses Firebase for event, usage tracking and Crashlytics for crash reports. So before you start work on it, you'll need to go to your Firebase console and create an app for this project, then download its GoogleService-Info.plist file and copy it in this folder.
If you updated the app id in the previous step, in the local config file, use the same bundle identifier in Firebase console.