Put it after a short message alert, then follow it with a second reminder if nobody replies. Start with the WhatsApp Message Sound, let this clip carry the reminder, and close with Olha a Mensagem when the check-in is still unfinished.
關於此聲音
This is a very short Portuguese voice clip, lasting about two seconds, in which a speaker delivers the line about needing to do check-in in a clipped, matter-of-fact tone. It feels impatient and slightly exasperated, like a nudge sent when someone is running late with a simple task. That blunt, everyday delivery makes it easy to recognise and instantly relatable in a chat.