Place it at the end of a short chat or reaction edit, after the favour or kind message has been shown on screen. Open with the WhatsApp Message sound to signal the incoming text, then let this clip answer it, closing the scene on the thank you.
Über diesen Sound
This is a short voice clip of someone stretching out the Italian word for thank you into a long, playful 'grazieee' that lasts just under three seconds. It feels warm and a little over the top, like a hug in audio form, turning a simple thanks into something memorable and fun to hear again.