Addition based on a selection in a list.

Hi,

I'm trying to make an addition based on the selection in a list.

So in my exemple, in the J collumn, G is 4 times so I3 should show 4.

I tried the SUMIF (SOMME.SI in french) formula but it doesn't seem to be working because I don't have another number to add to the formula.

The J collum is slected based on a list that I created in another tab and H3 use the same list.

Thanks in advance!