Bug fixed

app.py

@@ -190,7 +190,7 @@ with gr.Blocks(theme=gr.themes.Soft(), head=head_html, css="style_overrides.css"
         timestamp = datetime.now().isoformat()
         for i, s in enumerate(ndiff(prev_message, message)):
             diff = char_diff_obj(s[0], i, s[-1], timestamp)
-            if diff['type'] in ('+', '-'):
+            if diff['t'] in ('+', '-'):
                 history.append(diff)
         return message, history