SAP B1 how to add user defined field to Project management Documents?

We are using SAP B1 with non-perpetual inventory. In Project management - Documents window, the costs of Production seems like 0 (Goods Issue- Issue For Production), as it did not make a journal entry.

I want to add a User Defined Field with FMS of the price area from goods issue to the documents table (highlighted as yellow) below. So that I can calculate the real cost of the project. (I think I can handle this part.)

However when I go the User Defined Field Management page I cannot see this area. There is only, title,stages Open Issues and SubProject Title areas in there.

Is it possible? How can I add User Defined Field to this area ?