Okay, so you record your message, and then you tap the little smiley face emoji icon right next to the microphone, and then you can swipe along the options and choose the one you like. And then you press send. Now it won't immediately work, you have to give it like 10 seconds and then it'll transcribe your voice into text, and then it will apply the voice changer. So just trust that it works. You just have to give it a second.