Hello everyone. I am trying to copy the Confirmation Date of a SO to each line. I created the date field but I am not able to tell Odoo to fetch this date. I cant find any tutorials that address this problem. This is my last attempt code:

for record in self:

  record[("x_studio_fecha_de_entrega")] = sale.order.confirmation_date.date() 

This is the error:

ValueError: <class 'NameError'>: "name 'sale' is not defined" while evaluating
'for record in self:\n  record[("x_studio_fecha_de_entrega")] = sale.order.confirmation_date.date()'

Any help would be appreciated.

Best regards.