app.py

import streamlit as st
from gtts import gTTS 
from io import BytesIO

x = st.slider('Select a value')
st.write(x, 'squared is', x * x)

sound_file = BytesIO()
tts = gTTS('Add text-to-speech to your app', lang='en')
tts.write_to_fp(sound_file)

st.audio(sound_file)