[!] Automatically assigning platform `iOS` with version `9.0` on target `Runner` because no platform was specified. Please specify a platform for this target in your Podfile. See `https://guides.cocoapods.org/syntax/podfile.html#platform`.

The solution for this is noted below

[!] Automatically assigning platform iOS with version 9.0 on target Runner because no platform was specified. Please specify a platform for this target in your Podfile. See https://guides.cocoapods.org/syntax/podfile.html#platform.

Solution

flutter clean
cd ios
arch -x86_64 pod install
cd ..
flutter run

Try other methods by searching on the site. That is if this doesn’t work