Flutter – I can't found buildscript in build.gradle

I know that androidbuild.gradle includes buildscript. but build.gradle in my project doesn’t have buildscript. so I can’t solve following error.

C:/Users/JG-H/.gradle/caches/transforms-3/2ae0bf9da71bed198914dc960cb2262f/transformed/jetified-kotlin-stdlib-common-1.9.0.jar!/META-INF/kotlin-stdlib-common.kotlin_module: Module was compiled with an incompatible version of Kotlin. The binary version of its metadata is 1.9.0, expected version is 1.7.1.
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┌─ Flutter Fix ──────────────────────────────────────────────────────────────────────────────┐
│ [!] Your project requires a newer version of the Kotlin Gradle plugin. │
│ Find the latest version on https://kotlinlang.org/docs/releases.html#release-details, then │
│ update C:UsersJG-HDesktopFlutter practice 20242.little │
│ spicyweather_appandroidbuild.gradle: │
│ ext.kotlin_version = ” │
└────────────────────────────────────────────────────────────────────────────────────────────┘

how can i find buildscript in build.gradle??
following is my buildgradle.’

allprojects {
    repositories {
        google()
        mavenCentral()
    }
}

rootProject.buildDir = '../build'
subprojects {
    project.buildDir = "${rootProject.buildDir}/${project.name}"
}
subprojects {
    project.evaluationDependsOn(':app')
}

tasks.register("clean", Delete) {
    delete rootProject.buildDir
}

i have copied buildscript in my other project.
but it can’t be run.