neo geo "TEST" button (change difficulty)

[obiwansith]

Please i need help!!!!! .........
What would be the push button to enter the test menu in neo geo
Example ---- in MAME pC is the F2 button ....

[acris]

neogeo use fba libretro core.
you need to use retroarch (hotkey+B) to change core options or add unibios in neogeo.zip

https://github.com/recalbox/recalbox-os/wiki/Use-Neogeo-Unibios-(EN)