Place it at the end of a begging or favour-asking scene, right before the cut to the other person's reaction. Follow it with an emotional damage hit for an over-the-top refusal, or place a bruh moment straight after when the request gets shut down flat.
About this sound
This is a 1.7-second voice clip of a young anime-style girl sweetly calling out 'Onii-chan, Onii-chan' twice in Japanese. The high, pleading delivery feels cute, clingy and playfully embarrassing at once, which is why listeners use it to tease someone acting like an adoring little sister.