I can see how to wrap the text in individual cells within fields in a table frame on a layout on ArcGIS Pro. But I can't see how to wrap text within a field heading. See screenshot of my table frame below, all 3 of those columns could be a lot narrower if the field heading could wrap text. 
From the screenshot on this article - https://www.esri.com/about/newsroom/arcuser/ten-tips-for-tables-in-layouts - it appears to be possible, but I can't see how to toggle the option anywhere! I am using ArcGIS Pro 3.6.1. Any help much appreciated!