If you are wanting to add Windows Store apps to the Parsec Approved Apps list, you may find that the app does not appear in the list when you open it.
This is due to how Microsoft handles Microsoft Store Apps in full screen mode.
You can add your game to approved apps by following this work around.
WARNING: This will approve ALL Windows 10 apps, including Calendar, Mail, Microsoft Edge, Windows Settings menu and any app you download from the Microsoft Store. There is currently no way to distinguish these apps apart.
1. Open the Windows 10 Calculator App
2. Select the Calculator in your Approved Apps list.
3. Open your Windows 10 / UWP App
4. Close Calculator
Your Windows 10 App will now be enabled in approved apps