Creating Single-State County-Level Map using Plotly Express (NOT figure factory)

I have already made county-level maps using plotly’s figure factory. However, I recently read here (https://plotly.com/python/county-choropleth/) that “This is no longer the recommended way to make county-level choropleth maps”, and to use a geojson or mapbox approach instead.

However, when I try to use plotly express to do this, I am unable to put any states in the “scope” field of px.choropleth. Per here (https://plotly.github.io/plotly.py-docs/generated/plotly.express.choropleth.html), scope only takes in one of 'world' , 'usa' , 'europe' , 'asia' , 'africa' , 'north america' , or 'south america'.

So this leads to my question: is there actually a way to make a single-state county-level chloropleth maps in plotly, or should I stick with figure-factory, which accepts states in the scope field?