Yeah it’s a known issue, there are some workarounds in this issue, it does involve tampering with the Streamlit install:
It accepts Twemoji icons but it should also accept types supported by st.image.
EDIT: loading a favicon and displaying it works for me:
from PIL import Image
import streamlit as st
im = Image.open("favicon.ico")
st.set_page_config(
page_title="Hello",
page_icon=im,
layout="wide",
)
Fanilo