No option for trendline

I am trying to add a trendline to a question, but it doesn’t give me the option in the visualization, only ‘goal’. I’m using a bar visualization, on a time series X axis, and am only grouping by the single date value. As far as I’ve seen online that should be all I need right? What else do I need to do in order to get a trendline option?

I’m running v0.30.3.

Not sure about such an old version, but on the latest, it appears when you group by date. Have you tested with 0.33.4?