Reyke Key Finder, 80dB+ RF Item Locator Tags with 131ft. Working Range, Wireless Remote Tracker for Wallet, Phone, Glasses, Pet, 1 RF Transmitter & 4 Receivers

The exact one isn’t available any longer but here is a similar version https://a.co/d/0iZplXHW

You want this kind of key-tracker that works on RF, or if they have facility-wide wifi they make ones that go on wifi. Recommendation: use nano-tape or some other vigorous adhesive to glue the finder-remote to the wall as if it's just another light switch or whatever, or inside a closet or behind something you can direct staff to but she won't mess with it, or she'll hide that too.