如何在dash中访问请求头

import dash
from dash import dcc, html
from dash.dependencies import Input, Output

app = dash.Dash(__name__)

app.layout = html.Div([
    html.H1("访问请求头示例"),
    html.Div(id="header-output")
])

@app.callback(
    Output("header-output", "children"),
    [Input("header-output", "id")]
)
def update_header_output(input_value):
    headers = dash.request.headers
    header_list = [html.Div(f"{header}: {value}") for header, value in headers.items()]
    return header_list

if __name__ == '__main__':
    app.run_server(debug=True)