Multi-module project

I'm trying to configure axion-plugin with my multi-module project just as it says the documentation "https://axion-release-plugin.readthedocs.io/en/latest/configuration/basic_usage/".

```
buildscript {
repositories {
google()
jcenter()
maven("https://plugins.gradle.org/m2/")
}
dependencies {
classpath("com.raxdenstudios:android-plugins:0.15")
}
}

plugins {
id("io.gitlab.arturbosch.detekt") version("1.10.0")
id("pl.allegro.tech.build.axion-release") version("1.12.0")
}

scmVersion {

localOnly = true
}

allprojects {
project.version = scmVersion.version
repositories {
google()
jcenter()
}
}

tasks {
val clean by registering(Delete::class) {
delete(buildDir)
}
}
```

but.. I receive this error -> "Extension with name 'scmVersion' does not exist. Currently registered extension names: [ext]"