why .ips ? pls .gba version not playing
The .ips file is needed because hosting the .gba file isn’t exactly... legal. You use the .ips to patch a .gba file you find on your own; instructions are included above. If you do that and are still have issues playing the game, then it’s possible that the .gba file you downloaded wasn’t functional and you could try locating another one.
These instructions should be able to walk you through the process: https://www.pokecommunity.com/showthread.php?t=426058