Hello i have this error on my flutter app, how can fix this?

Flutter error:

Xcode's output:
↳
    ../../../../.pub-cache/hosted/pub.dartlang.org/numberpicker-2.1.2/lib/src/numberpicker.dart:197:66: Error: The getter 'bodyMedium' isn't defined for the class 'TextTheme'.
     - 'TextTheme' is from 'package:flutter/src/material/text_theme.dart' ('../../../../development/flutter/packages/flutter/lib/src/material/text_theme.dart').
    Try correcting the name to the name of an existing getter, or defining a getter or field named 'bodyMedium'.
        final defaultStyle = widget.textStyle ?? themeData.textTheme.bodyMedium;
                                                                     ^^^^^^^^^^
    ../../../../.pub-cache/hosted/pub.dartlang.org/numberpicker-2.1.2/lib/src/numberpicker.dart:199:29: Error: The getter 'headlineSmall' isn't defined for the class 'TextTheme'.
     - 'TextTheme' is from 'package:flutter/src/material/text_theme.dart' ('../../../../development/flutter/packages/flutter/lib/src/material/text_theme.dart').
    Try correcting the name to the name of an existing getter, or defining a getter or field named 'headlineSmall'.
            themeData.textTheme.headlineSmall
                                ^^^^^^^^^^^^^
    Failed to package /Users/riccardo/Desktop/Progetti/Personali/quoteflutter/ios/...
    Command PhaseScriptExecution failed with a nonzero exit code
    note: Run script build phase 'Run Script' will be run during every build because the option to run the script phase "Based on dependency analysis" is unchecked. (in target 'Runner' from project 'Runner')
    note: Run script build phase 'Thin Binary' will be run during every build because the option to run the script phase "Based on dependency analysis" is unchecked. (in target 'Runner' from project 'Runner')

Could not build the precompiled application for the device.

Error launching application on iPad di Riccardo.