Put it at the beat where a spoken question goes unanswered, right before you cut to the reaction shot. Follow it with the nope meme sound when the bit turns into a flat refusal, keeping this clip first in the sequence.
About this sound
A very short voice clip of Deimos from Madness Project Nexus saying 'I dunno' in a flat, unbothered tone, lasting under a second. It feels deadpan and dismissive, like a shrug turned into words, which makes a simple non-answer sound funnier and more awkward than staying silent.