Set Job Task No. with extension

Hi everyone,

I'm finding a problem finding the event where I can set the "job Task No." before the insert of the registry.

In a job card, when I'm trying to create a Job Task, I want to create it without setting the Job Task No, which I want to be filled when inserting, adding for example, the date. Which event can I sue fro this purpose? I'm trying to use the events from the "Job Task" table, but I can't find the correct way.... Is possible to develop this with extensions?

Thnak you very much