How to do dot density in ArcGIS Online?

I have some census tract polygons with language spoken at home attribute data behind them. I created them in ArcMap and produced a dot density map. However, after importing to AGOL it's only the polygons. I am aiming to create a swipe map comparing two maps visualizing the growth of language outwards from the city to suburbs over 20 years.

Here's a before and after image of the tracts in ArcMap, then AGOL: