Good morning, everyone!
I need to ins ert a specific value in one cell of the row when the new row is added.

If Object.ItemType = PredefinedValue("Enum.ItemTypes.Cartridge") Then
 Items.ItemType.CurrentData.Quantity = 1;
EndIf;

If I insert this code in BeforeAddRow an error occured. If in OnChange the val ue is inserted, but when a row is deleted it produces an error again. Which event should I use for this task? And also I would like to know how to copy rows in the tabular section (when a user clicks Copy button).
Thanks in advance

You must use "OnStartEdit" event.

Thanks! That worked.