star wars clone wars republic heroes help!!

Hi there
i downloaded 4245 star wars the clone wars republic heroes (E)(M5)(BAHAMUT).nds for my sons r4 card. He is stuck on one bit of it so i tried to download the cheats file to help him past this bit but the cheat option (Y) isnt coming up
can anyone help me pls

Depends on your R4's firmware.

how do i check what firmware?
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its a revolution for DS r4 card with the standard firmware