如何让Dash使用Choropleth图

import dash
import dash_core_components as dcc
import dash_html_components as html
import plotly.express as px

app = dash.Dash(__name__)

data = {
    'Country': ['China', 'USA', 'India'],
    'Value': [10, 20, 30]
}

fig = px.choropleth(data_frame=data, locations='Country', locationmode='country names', color='Value')

app.layout = html.Div(children=[
    html.H1(children='Choropleth Map'),
    dcc.Graph(figure=fig)
])

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