Here's why:
* Igglybuff is not available in FireRed. It was introduced in Generation II games (Gold, Silver, and Crystal).
* Egg hatching in FireRed is based on a timer, not steps. You need to wait a certain amount of time for an egg to hatch, and this time varies depending on the Pokémon's species.
If you're playing a different Pokémon game where Igglybuff is available, you can find the number of steps it takes to hatch an Igglybuff egg in that game's strategy guides or online resources.