Json API Transisition Time for segments

Hi there,
i have a problem with my json api Call… i would like to fade in/ fade our when i set the LEDs… Is this possible? This Code works:


But when i Add a Transition it makes no changes:


is it possible to add this? Or any other way to get a fade in / out in wled?
Fade in or out via the api is not possible, this will crash my system…