Change gba game on screen display location

[microwavegobrrrr]

How do I change the GBA game display location to the middle of the screen instead of the top. It looks like this:

I want it to look like this:

[Lilo2020]

Open RetroArch while you’re in the game. Now go to settings/video/scaling adjust the Viewport Anchor Bias Y to 0.50

Now go to Quick Menu look for Overrides and select “Save Core Overrides” to save your settings.