COVID-19 Exposure Logging on the iPhone
To turn on COVID-19 Exposure Logging on your iPhone first head to Settings > Privacy > Health.
At the top there is the COVID-19 Exposure Logging option, which is set to off by default. Tap it.
If the option is available in your region (it is currently not in the UK, for instance,) you see the option to toggle Exposure Logging to on.
Even if it is available, you can only turn Exposure Logging on if there is also a recognized app (normally from a health authority,) to link it with on your iPhone. Such apps are not available in the U.S., UK, or many other countries yet, but are expected soon.
When Exposure Logging is activated, users will be able to see if there have been requests to check their exposure log. To see this information, tap the Exposure Checks option.