You can create KorGE plugins by creating a multiplatform artifact and creating a .korge-plugin file along the artifact and your .pom:

You have an example here:

afterEvaluate {
    extensions.getByType<PublishingExtension>().apply {
        val publication = publications["kotlinMultiplatform"] as MavenPublication
        publication.artifact(File(buildDir, "korge-plugin.korge-plugin").apply {
            val node = Node(null, "korge-plugin").apply {
                appendNode("variables", mapOf("ADMOB_APP_ID" to "string"))
                appendNode("android").apply {
                    appendNode("init", mapOf("require" to "ADMOB_APP_ID")).setValue("try {, \"\${ADMOB_APP_ID}\") } catch (e: Throwable) { e.printStackTrace() }")
                    appendNode("manifest-application", mapOf("require" to "ADMOB_APP_ID")).setValue("<meta-data android:name=\"\" android:value=\"\${ADMOB_APP_ID}\" />")
                    appendNode("dependencies").apply {
                        appendNode("dependency", mapOf("require" to "ADMOB_APP_ID")).setValue("$playServicesVersion")
                appendNode("cordova").apply {
                    appendNode("plugins").apply {
                        appendNode("cordova-plugin-admob-free", mapOf("ADMOB_APP_ID" to "\${ADMOB_APP_ID}"))

This file helps KorGE to identify what kind of things has to do at compile-time with Android or Cordova, in addition to which variables does the plugin need to work properly.