buildscript ext does not work

[plugie]

URL of codelab https://github.com/google-developer-training/basic-android-kotlin-compose-training-dessert-clicker/tree/main

In which task and step of the codelab can this issue be found?
Set up dependencies

Describe the problem
buildscript ext does not work

Steps to reproduce?

1. Add in build.gradle.kts
   buildscript {
   ext {
   lifecycle_version = '2.5.1'
   }
   }
2. See error...
   Unresolved reference: ext

Versions
Android Studio version: Giraffe 2022.3.1 Patch 2
API version of the emulator: 32

Additional information
Include screenshots if they would be useful in clarifying the problem.

[patrykharanczyk]

I fixed it this way for myself:

In build.gradle.kts instead of that sample code define it this way:
buildscript { extra.apply { set("lifecycle_version", "2.5.1") } }

Then in app/build.gradle add two things
Before dependiencies block add:
val lifecycle_version = rootProject.extra["lifecycle_version"]
In dependencies add:
implementation("androidx.lifecycle:lifecycle-viewmodel-compose:$lifecycle_version")

Hope this helps you.