If you face POD related issue on your flutter app then simply follow these few steps.
The first simple go to your ios directory by command line then run POD update
POD update
Solution 2
# Completely clean first
flutter clean
rm -Rf ios/Pods
rm -Rf ios/.symlinks
rm -Rf ios/Flutter/Flutter.framework
rm -Rf ios/Flutter/Flutter.podspec
# Remove pod file
rm ios/Podfile
# Run flutter again
flutter run