I lost my iPhone
it might be off now but it should still say where its at even if its dead
iPhone 12, iOS 16
Find your lost iPhone or iPad with Find My - Apple Support
The phone will not appear if any of these things have occurred.....
- The battery has run down
- The phone has been powered off (most models)
- The phone does not have an Internet connection where it is currently located
Unfortunately, there is nothing you can do about this other than keep checking a few times each day to see if the status of the phone has changed.
Good luck.