translytical-task-flow button not working?

Hi paulos​ -From your screenshot, no function is selected yet. Once one is, you’ll see Workspace / Function set / Function name under “Data function,” and the parameter fields appear below that.   Click the fx icon, pick your function in the OneLake catalog. If it isn’t listed, check:

The function returns a string (-> str). Non-string returns are hidden from the button.                       The User Data Functions item is published and you have access to its workspace.                      Desktop is signed in to the same tenant.                                                                                             Then map each parameter (e.g., a SELECTEDVALUE(Table[Id]) measure for the Id). Note the action only runs after publishing to the Service.

Ref: Create data function buttons - Power BI | Microsoft Learn

 Hope this helps.