FAILURE: Build failed with an exception.

• Where:

Build file ‘C:UsersHPStudioProjectsDoctor_Appointmnent_Appandroidappbuild.gradle’ line: 9

I

• What went wrong:

A problem occurred evaluating project’: app’.

Could not get unknown property ‘buildToolsVersion’ for extension ‘flutter of type FlutterExtension.

• Try:

Run with –stacktrace option to get the stack trace.

Run with –info or-debug option to get more log output

• Where:
  Build file ‘C:UsersHPStudioProjectsDoctor_Appointmnent_Appandroidappbuild.gradle’ line: 9

• What went wrong:
  A problem occurred evaluating project ‘:app’.

Could not get unknown property ‘buildToolsVersion’ for extension ‘flutter’ of type FlutterExtension.

• Try:

Run with –stacktrace option to get the stack trace.
Run with –info or –debug option to get more log output.
Run with –scan to get full insights.

• Get more help at https://help.gradle.org

BUILD FAILED in 1s
Error: Gradle task assembleDebug failed with exit code 1