Support for custom Power Query Functions in Dataflows
We really need support for custom functions in Dataflows. This is a huge limitation to dataflows today.
As Oliver and Aaron have mentioned: https://ssbipolar.com/2018/12/12/custom-functions-in-power-bi-dataflows/
Olivier Travers commented
It's unintuitive, but you can already create an M function in Dataflows. Start from a blank query, paste your code, and make sure to uncheck Load (right click on the function in the left pane).