Remove random integer in range from index once used

I’ve tried getting the lenght of the array but it is the same, I’ve set the number of loops to the max array index and I had 4 locations not filled. If it get twice the same index it don’t spawn the item.

And for the remove node, the remove index is working to keep the other target points for the next loop? I’ve tried but it don’t seems to work.

EDIT: just wrote the doc, looks like remove index is what I need but it don’t work…

Arrays are a nightmare to me, I don’t get the logic behind it.