Place it right after the reveal in a reaction edit, then follow it with a longer cheer to keep the excitement going before cutting to the next scene. For a bigger shock, put a sharp impact just before it, so the surprise builds and the payoff lands.
About this sound
This 4.5-second clip is a drawn-out voice exclaiming OMG and wow in one long rush, stretching both words until they sound completely overwhelmed. It feels giddy, surprised and a little over the top, like the exact moment someone sees something unbelievable and cannot hold the reaction in.