Plotly Express choropleth map

I am trying to make a choropleth map of Colombia. I create an example dataframe to prove if the map works.
I am using a GeoJson of the colombian cities and I set the featureidkey properly (I guess), but the map doesn’t work.
Here is my code and the GeoJson is here: Hello.md · GitHub

df=pd.DataFrame({‘Ciudad’:[‘BOGOTÁ, D.C.’,‘MEDELLÍN’,‘QUIBDÓ’],‘Muertos’:[30,80,90]})

cities = json.load(open(’./data/MunicipiosVeredas1MB.json’, encoding=‘utf-8’))

dcc.Graph(

    figure=px.choropleth(

        df, 

        geojson=cities,

        featureidkey='properties.MPIO_CNMBR', 

        locations='Ciudad', 

        color='Muertos',

        color_continuous_scale="Viridis",

        projection="mercator"

    )

)