Apple added the Exposure Notifications API in the iOS 13.5 iPhone update with the exposure loggings, just like it has been released on Android. If you want, you can switch it off. Here's how to do so:
This works if you have a health tracking app installed. If you do, your iPhone will send out random Bluetooth beacons to devices around you. It will collect beacons from phones that you have been around for at least 10 minutes.
If someone around you has marked themselves as Infected via their health tracking app, your phone will tell you that you may have been exposed to Covid-19.
Note: This works if you have walked near them in the last 14 days.