modelize FFA coproducts on GHGenius 4.03c

HI, I would like to better understand how to correctly modelize Free Fatty Acis Co-Product, from biodiesel production, on the sheet Co-Prods, in GHGenius 4.03c. 
What is the right calculation to obtain the number to paste on the cell '' Placeholder Co-product (kg) '' ?
Is there a second step to do before clicking on  ''Run Program'' ?
Thanks

*Free Fatty Acids