Struggling to remap my buttons

[Cherriesd27-wq]

I've been trying multiple ways to write it in config and i cant figure out the right way. I want to map Y=B B=A. my config looks like that :
[general]
backlight=64
backlightSteps=5
directBoot=false
useGbaDb=true
useSavesFolder=true

[video]
scaler=matrix
colorProfile=none
contrast=1.0
brightness=0.0
saturation=1.0

[audio]
audioOut=auto
volume=127

[advanced]
saveOverride=false
defaultSave=sram_256k

[input]
RIGHT=RIGHT,CP_RIGHT
LEFT=LEFT,CP_LEFT
UP=UP,CP_UP
DOWN=DOWN,CP_DOWN

[input]
Y=B
B=A

If anyone could show me why it doesnt work it would make my day