Starting the simulator
Once you have your React Native project initialized, you can run
npx react-native run-ios inside the newly created project directory. If everything is set up correctly, you should see your new app running in the iOS Simulator shortly.
Specifying a device
You can specify the device the simulator should run with the
--simulator flag, followed by the device name as a string. The default is
"iPhone 13". If you wish to run your app on an iPhone SE (2nd generation), run
npx react-native run-ios --simulator='iPhone SE (2nd generation)'.
The device names correspond to the list of devices available in Xcode. You can check your available devices by running
xcrun simctl list devices from the console.
Specifying a version of device
If you have multiple iOS versions installed, you also need to specify it's appropiate version. E.g. run
npx react-native run-ios --simulator='iPhone 13 Pro (15.5)' in order to specify the iOS version.
Specifying an UDID
You can specify the device UDID returned from
xcrun simctl list devices command. E.g. run
npx react-native run-ios --udid='AAAAAAAA-AAAA-AAAA-AAAA-AAAAAAAAAAAA'.