How to add preposting to customer invoice header

Hello,

I am trying to fill preposting on header level of customer invoice but its blocked for use (greyed out). I read that I have to set up the M104 and M103 with C58 control type, so I did but still can’t manage to fill data on invoice.

The customer invoice was created from a delivered order on the “create customer invoice” tab and prepostings on invoice line are inherited from CO line. To be able to add code part values on IP2, I think I have to add them on preposting of invoice header.

IP2 is configured with the preposting AC2 control type.

If you have any idea on how i could manage to add preposting on header level of a planned customer invoice, I’d be grateful to you if you could share some ideas.

Thanks 

Tanya