Hi, thank you so much for your support 😄
Alright so all you gotta do is:
1) Click on the "App Center" which is of green color on the same pane as Minimize, Maximize, Close etc for NOX.
2) Click on any random app. Could be anything, doesn't matter
3) When you click any app it will say "Open in Play Store App", so click that and then it will bring you to google play page, click on Sign In and enter any valid Gmail ID's credentials.
4) Go back to FEH and now it will work!
Hope this helps!