Scatter Map Box Marker

[mirenchu13]

Hello, I am trying to plot a scatter map box graph which is actually working. This is the code I have used:
mapboxt = open(“mapbox_token.txt”).read().rstrip() #my mapbox_access_token

scatt = go.Scattermapbox(
lat=df_XY[‘Latitude’],
lon=df_XY[‘Longitude’],
mode=‘markers’,
text=df_XY[‘1-Noise’],
marker=dict(
size=10,
showscale=True,
colorscale=‘Viridis’,
symbol = ‘y-down’,
cmin=0,
color = df_XY[‘1-Noise’],
cmax=df_XY[‘1-Noise’].max()))
layout = go.Layout(title_text =‘Turbine Losses’,
title_x =0.5, width=1350, height=800,
mapbox = dict(center=go.layout.mapbox.Center(lat=df_XY[‘Latitude’][0],lon=df_XY[‘Longitude’][0]),
accesstoken= mapboxt,
zoom=6,
style=“light”
))
fig.layout.coloraxis.colorbar.title = ‘1-Noise’
fig=go.Figure(data=[ scatt], layout =layout)
fig.show()

This is the graph I obtained:

However, I would like to have the ‘y-down’ markers instead of the circles. However, when I changed the symbol parameter for ‘y-down’ I get an error saying Javascript error: Mapbox error

Thanks in advance.