I am able to create flavors for my Android application, however I want to move the code in a custom gradle file. Doing this, it gives me this error: "Unresolved reference: android". Why?

flavor-config.gradle.kts:

android {
    flavorDimensions += "version"
    productFlavors {
        create("remote") {
            dimension = "version"
            isDefault = true
        }

        create("local") {
            dimension = "version"
            versionNameSuffix = ".local"
        }
    }
}

build.gradle.kts:

android {
...
}
apply(from = "flavor-config.gradle.kts")