Hello @thomaso34696569
I would suggest to download and import some external library (min.js) which can generate random IV.
Create new JS file and paste code from min.js and load that JS file (loadLibrary("cus:yourfile.js");) in workflow or other JS where you want to generate IV.
I would say there is not default function in ACC to do it therefore you can do suggested above.
Regards,
Milan