Place this clip right after the on-screen decision lands, as the final beat of the scene. Follow it with the Bruh Sound Effect if the agreement causes instant regret, or precede it with the Oh My God Meme Sound to build disbelief first.
About this sound
This two-second clip is a single casual 'okay' spoken in an anime voice, flat and relaxed with nothing else behind it. It feels dry and unbothered, like a verbal shrug, making agreement sound resigned rather than enthusiastic and giving any moment a quietly funny, going-along-with-it edge.