You can't, or at least not if you were already able to. Firebug only works in Pokemon Indigo if you were using it before they fixed the game. Now, only those who already have Firebug installed and in use can use it to hack.
i can tell u it doesnt work because they updated the Pokemon glitch but not the money glitch... by the crush am thinking the same thing...
An easy way to get money in Pokemon Indigo is to keep fighting gym leaders.
there is NONE
By battling, of course.
BATTLE
just keep batteling
you can buy it for some money...
you can buy it for some money...
Get more money and Capture them
all you gotta do is battle
press alt+F4
use your money to buy them from the shop.