a code line added for testing

app.py

@@ -350,6 +350,8 @@ if st.session_state.video_button:
 
     step3_col1, _, _ = st.columns([4, 3, 5])
 
+    st.write(os.path.isfile('generated_video.mp4'))
+
     with step3_col1:
         st.video(
             # os.path.join('avatar_videos', 'generated_video.mp4')