how do i use the gameshark rom? https://www.romulation.org/GBA/0236_-_GameShark_GBA_(U)_(v1.0)_(Unl).rar.html here is the url
but to use gameshark on an emulator ( if thats what you wanna know) on VBA: go to Cheats > Cheat list... then click on "add gameshark code" on Nocash: press F2 , the type in the code , then select the "Gameshark V1/2" option on the bottom of the window