Start a duel. Before the coinflip screen, open GG and pause the game.
Load the card substitution text file, ensuring Items, Values, Freeze is checked.
Change the addresses to the card you want, just as you’ve already done in the picture.
Close GG and you should draw those cards at the start of the duel.
One thing to note is you’re not supposed to freeze those top three addresses (Top Card, 2nd Card, 3rd Card). They need to be unfrozen or it will cause issues later….