solving export issue

app.py

@@ -100,7 +100,7 @@ def process_fn(audio_file_path, model_name):
         filename = f"demucs_{model_name}_{stem_name.lower().replace(' ', '_')}.{extension}"
         output_path = Path(filename)
 
-        signal.export(output_path, format=extension)
+        save_audio(signal, output_path)
         outputs.append(str(output_path))
 
     return tuple(outputs)