How to find out the iPhone stolen or lost
If you lost something, doesn't matter but smartphone. Some of them have lost their smartphones or mobile phones or iPhones unfortunately though they don't lose any other things in their life. So, is it possible to get it back? Hardly yes in very few cases.
How to get back if iPhone is lost or stolen?
I was going through one more article, like, how to make sure your iPhone is discoverable if stolen? I got the reply as below and it seems the better one to go through it and follow the steps given.
"The first step you'll need to do to prevent your iPhone from becoming undiscoverable if it gets into the wrong hands is to turn off what someone is able to access when your iPhone is still locked.
Open Settings on your iPhone
Tap on 'Face ID & Passcode' or 'Touch ID & Passcode'
Enter your passcode
Scroll down to the Allow Access When Locked section and toggle off Control Centre and USB Accessories
The next step you'll need to take to ensure you'll still be able to find your iPhone if it is turned off, is to turn on location services.
Open Settings on your iPhone
Head to Privacy
Tap on Location Services at the top
Toggle Location Services on
The last step is to make sure the Find My network is on and Find My iPhone is on.
Open Settings on your iPhone
Tap on your name at the top to open Apple ID settings
Tap on Find My
Click on Find My iPhone at the top
Toggle on Find My iPhone, Find My Network and Send Last Location
After all these steps, when you then go to power off your iPhone, you should now see a greyed out message under the 'Slide to Power off' option that says 'iPhone Findable after Power Off'".
Courtesy: https://www.pocket-lint.com/
You can also check this article from Apple https://support.apple.com/en-us/HT201472 for better trace out.