OK, here's how you can select which App uses which Graphics card:
Go to your Windows Settings by pressing and holding the Windows Key on your Keyboard + I.
Click on System.
Click on Display.
On the Display Settings page, scroll down and click on "Graphics Settings"
Where it says "Choose an App to set preference" click the drop down box and then select "Microsoft Store App"
Now click the drop down box that says "Select an App"
Scroll up and down and find the App you want to run using a specific graphics card.
Click on the App and then click the "Add" button.
The App you selected will now be shown.
Click on the App's "Option" button.
Select which graphics card you want to use for this specific App.
Power Saving will be your Intel Graphics Card.
High performance will be your AMD Radeon Graphics Card.
Click on the "Save" button when you have made your selection.
From now on, whenever you run this App it will use the graphics card you have selected.
I hope this helps! Let me know if you have any questions.