Change access method for Graphite Data Source

I have Graphite running locally and am trying to connect it to my first Grafana dashboard. The difficulty I’m having, however, is that the default access method is “Direct” – which will not work with Graphite running on localhost. The docs suggest that using the “Browser” access method would fix this problem, but I cannot find a way to select this method. For reference, here’s what I see when adding/editing the data source:

Can I change this setting or is it not available with the free version of Grafana?