Update field when task is completed

Update field when task is completed

Hi,

I want a field to be automaticly updated when I mark a specific task as closed.

So, I have a task in the module 'Leads' with the topic 'Factureer kosten van {COMPANY_NAME}'. When this tasked is closed, I want that the close date is filled out in the field 'Date close factuur'

How can I do this?