To ensure the graphics card is being used, go to Settings > System > Display > Graphics > Select "Desktop app" on the drop-down menu > Browse > Locate the game file .exe
(If it is a Steam game, the game folder can be located at C:\Program Files\Steam\steamapps\common if you did not change the default folder).
After selecting the game .exe file, it will show on the list, select it > Options > Select the graphics card > Save.