Got it to work:
locations = DF[['Longitude','Latitude']]
locations = locations.values.tolist()
isochrones = client.isochrones(locations = locations,
profile='driving-hgv',
range=[900, 1800, 2700, 3600], ### 900 / 60 = 15 minutes
units="km",
attributes = ['area', 'reachfactor', 'total_pop'])
for iso in isochrones['features']:
folium.features.GeoJson(iso,style_function=styl_func).add_to(Map)