Hello, that option is in the Samsung keyboard, if I'm not wrong, I don't like the Samsung keyboard and I prefer Gboard XD, look for the option to create an avatar that should be near the emojis, it's a + sign, also for example in WhatsApp the profile photo or the stickers give you the option to create ones with your face or make them as you like...
Think it's in your camera to create a self one if you have S22 as it says open camera go all the way on the bottom to the right to more then go to top to AR ZONE and in AR Emoji Studio you can create one and then even add to your keyboard but that camera setting creates emoji figure of yourself
