Place it as the closing beat after the setup and reaction, not in the middle of the joke. Put the Bruh sound effect just before it to register disbelief, then let this clip end the scene, and follow with the Emotional Damage meme only if the next cut needs a bigger reaction.
About this sound
Zoio says é só isso, Brazilian Portuguese for that's all there is to it, in one unaccompanied spoken line lasting just over a second. The delivery is flat and matter-of-fact, giving it a dry, dismissive feeling, as if the speaker is closing a subject and refusing to add anything more. It has circulated as a reaction sound in Brazilian meme and Free Fire communities.