This

app.py

@@ -9,4 +9,4 @@ fill_masker = pipeline(model="bert-base-uncased")
 if query := st.chat_input("filler: "):
      ans = fill_masker(f"{query}[MASK]")
      with st.chat_message("User"):
-         st.write(ans[0][sequence])
+         st.write(ans)