Amplify flutter tutorial issue

I am trying to follow the tutorial for Amplify flutter but there appears to be an issue. I'm trying to follow it as closely as possible but I do not see the option for Boolean! onhttps://docs.amplify.aws/start/getting-started/generate-model/q/integration/flutter/#generate-the-models-locally There is only the option for Boolean. I continued on with the tutorial using Boolean. I get an error A value of type 'bool?' can't be assigned to a variable of type 'bool' because 'bool?' is nullable and 'bool' isn't.* which appears to be related. I tried to change the schema.graphql file to relect the correct isComplete: Boolean! instead of isComplete: Boolean... but not success when running flutter run

Not sure what is going on.... Thanks in advance