I've looked everywhere for ways to to download user-drawn graphics using ArcGIS JS API but have not found a solution. Is this something that can at least be done using a GP task?
I had some simple user drawn data and I was able to do this by using the following two libs:
https://github.com/Esri/arcgis-to-geojson-utils
https://github.com/mapbox/shp-write