Basemap

Use the basemap parameter to select a predefined basemap or specify a custom tile server with the tileUrl parameter.

Key	Provider / Type
osm	Open Street Map
otm	OpenTopoMap
streets	Esri Streets
satellite	Esri Satellite
hybrid	Esri Hybrid (satellite + labels)
topo	Esri Topographic
gray	Esri Gray w/ labels
gray-background	Esri Gray background only
hillshade	Esri Hillshade
national-geographic	National Geographic
stamen-toner	Stamen Toner (B/W)
stamen-watercolor	Stamen Watercolor
carto-light	Carto Light
carto-dark	Carto Dark

Make sure to respect the usage policy of each provider!