The following may help, from Two-factor authentication for Apple ID - Apple Support
When you sign in on a new device, you’ll get a notification on
your other trusted devices that includes a map showing the approximate
location of the new device. This is an approximate location based on the
IP address the device is currently using, rather than the exact
location of the device. The location shown might reflect the network
you're connected to, and not your physical location.
If you know you’re the person trying to sign in but you don’t
recognize the location shown, you can still tap Allow and continue
signing in. However, if you ever see a notification that your Apple ID
is being used to sign in on a new device and you're not the one signing
in, tap Don’t Allow to block the sign in attempt.