An incredible project to work on.
Currently you can stream War Child with a Prime Video subscription. If you already have Prime Video then you can stream this documentary right now without paying anything extra.
If you don't have Prime Video then you can still buy or rent War Child to watch online from 3 platforms - iTunes, Vimeo or Prime Video. It will cost you as little as $0.99 to rent the documentary and $2.99 to buy the documentary. If you can rent the documentary from Vimeo then please do as more of the revenue from the sale will go to the filmmakers.