I'm trying to add OneSignal to my flutter project and I followed this tutorial
https://documentation.onesignal.com/v5.0/docs/flutter-sdk-setup
but when I run
pod install
it shows error message like below
!] Invalid `Podfile` file: undefined local variable or method `s' for #<Pod::Podfile:0x00007f86880b7fa0>.
# from /Users/macmini1/Projects/flutter/my_project/ios/Podfile:58
# -------------------------------------------
# target 'OneSignalNotificationServiceExtension' do
> s.dependency 'OneSignalDynamic', '>= 2.8.8', '< 3.0'
# end
# -------------------------------------------
Anybody helps?