I am trying to setup android target for multiplatform project (androidMain) and get the following error:

Could not generate a decorated class for type KotlinAndroidTarget

Is there any guide how to add such sourceSet?

Have you checked these examples https://github.com/JetBrains/compose-jb/tree/master/examples Or the experimental ones https://github.com/JetBrains/compose-jb/tree/master/experimental%2Fexamples

Are those multiplatform or just android?

Multiplatform. The non-experimental don't share compose-ui. The experimental ones do share compose-ui code

Thanks! Will try that

No problem 👍🏻

This is a classloader isolation issue! Please ensure that you tell Gradle to load Kotlin Gradle Plugin and the Android Gradle Plugin together. My preferred approach for this is to load the plugins on the root project

plugins {
    kotlin("multiplatform") apply false
    id("<http://com.android.xyz|com.android.xyz>") apply false
}