Dialogue sound everytime a letter is typed



Hello I am a beginner at gms2 and I was wondering if anyone would help me
I am tryting to make some kind of platformer or something I am not sure yet
But at the intro of the game there is a dialogue while I was able to make it work and can t get my head around how to put a sound every time a letter is typed automatically I also don t seem to find any FX for free online, can anyone please provide me with some free comercial use FX and some help with the code?