how to save the file in the `database_reports` folder as below in flask python

I m currently deploy a machine learning model in web using flask python, Does anyone know how's the stored_file_name will be defined like? cause I m getting this error >> NameError: name 'stored_file_name' is not defined

app.py

new_data = pd.DataFrame(dicts).set_index("Month")
            ##df_predict = pd.DataFrame(transform, columns=["predicted value"])
            response = make_response(new_data.to_csv(index = True, encoding='utf8'))
            response.headers["Content-Disposition"] = "attachment; filename=result.csv"

            labels = [d['Month'] for d in dicts]
            
            values = [d['Predictions'] for d in dicts]

            colors = [ "#F7464A", "#46BFBD", "#FDB45C", "#FEDCBA",
                       "#ABCDEF", "#DDDDDD", "#ABCABC", "#4169E1",
                       "#C71585", "#FF4500", "#FEDCBA", "#46BFBD"]

            line_labels=labels
            line_values=values
            return render_template('graph.html', title='Time Series Sales forecasting', max=17000, labels=line_labels, values=line_values , filename=stored_file_name)


        
  
@app.route('/database_download/<filename>')
def database_download(filename):
    return send_from_directory('database_reports', filename)

<a href="">Download</a>