Since it can also measure vibration, set up a notification for vibration, go room to room and knock on each wall. You should have a good chance of zeroing in on it.
If you don’t find it the first time around, you can go around again checking smaller sections.
You can also use a broomstick to knock on the ceiling. And if you think you might have put it in a drawer, include knocking on countertops and desks.
Sometimes in situations like this, it was mounted, but came loose from the mounting and fell down, meaning it may be behind a piece of furniture or even stuck on a curtain rod.
Note: “acceleration” is the same as vibration in this context, so you can use the “Notify me when” app under Smart Setup for this purpose.