Here’s the full page about enabling Find My iPhone, Mac, and other devices. In short:
- Tap Settings > [your name] > Find My
- Ensure Find My iPhone says “On”
- If you’re asked to
- Click Apple menu > System Preferences > iCloud
- Turn on Find My Mac
If you don’t have Location Services turned on on your device, you’ll be instructed on doing that.
In iOS 13, Apple squeezed two apps into one: Find My Friends and Find My [Gadget] are now Find My. Here’s the icon you seek:
Also in iOS 13, Apple enabled Offline Finding, which gives you a chance of pinging it when there’s no Wi-Fi or cell signal. Apple’s full post on lost and stolen Macs.
And, hoping you never need it, here’s how to locate a lost or stolen device.