How can i connect my microphone to a mixer through an IPad?

[Erika92i]

hello to everybody , this is my first post here. I generally don't write , I always search and I always find, except this time.
I'm a singer and I'd like to use the iPad like a vocal effect pedal (with an app of course) during my live performances . So I suppose the iPad should be the filter between the microphone and the mixer entrance.
How can I do? I don't know with kind of cable I need .
I was almost buying irig but I thing it's not the solution.
Please help
Thanks