Problem with 1.9.23 KMP version. It's been fixed in 2.0 so it needs to be updated

sample/build.gradle.kts

@@ -17,9 +17,9 @@
 
 @file:Suppress("UnstableApiUsage")
 
-import org.jetbrains.kotlin.gradle.targets.js.testing.KotlinJsTest
-import org.jetbrains.kotlin.gradle.targets.native.tasks.KotlinNativeTest
 import org.gradle.api.tasks.testing.logging.TestExceptionFormat
+import org.jetbrains.kotlin.gradle.targets.js.dsl.ExperimentalWasmDsl
+import org.jetbrains.kotlin.gradle.targets.native.tasks.KotlinNativeTest
 import org.jetbrains.kotlin.gradle.tasks.FatFrameworkTask
 
 plugins {
@@ -82,6 +82,36 @@ kotlin {
 
         }
 
+        @OptIn(ExperimentalWasmDsl::class)
+        wasmJs {
+            browser {
+                webpackTask {
+
+                }
+                testTask {
+                    useKarma {
+                        useChrome()
+                    }
+                }
+            }
+            binaries.executable()
+//            browser {
+//                val rootDirPath = project.rootDir.path
+//                val projectDirPath = project.projectDir.path
+//                commonWebpackConfig {
+//                    outputFileName = "composeApp.js"
+//                    devServer = (devServer ?: KotlinWebpackConfig.DevServer()).apply {
+////                        static = (static ?: mutableListOf()).apply {
+////                            // Serve sources to debug inside browser
+////                            add(rootDirPath)
+////                            add(projectDirPath)
+////                        }
+//                    }
+//                }
+//            }
+//            binaries.executable()
+        }
+
 
         linuxX64("linux") {
             binaries {
@@ -207,6 +237,22 @@ kotlin {
             }
         }
 
+        val wasmJsMain by getting {
+            dependencies {
+                // implementation(kotlin(Deps.wasmJs.stdLib))
+                implementation(npm(Deps.wasmJs.Npm.libsodiumWrappers.first, Deps.wasmJs.Npm.libsodiumWrappers.second))
+            }
+        }
+        val wasmJsTest by getting {
+            dependencies {
+                dependsOn(commonTest)
+                implementation(npm(Deps.wasmJs.Npm.libsodiumWrappers.first, Deps.wasmJs.Npm.libsodiumWrappers.second))
+                implementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.9.0")
+
+                implementation(kotlin("test"))
+            }
+        }
+
 
 
 //        val nativeMain by creating {

sample/src/wasmJsMain/kotlin/com/ionspin/kotlin/crypto/sample/Main.kt

@@ -0,0 +1,12 @@
+
+
+import com.ionspin.kotlin.crypto.LibsodiumInitializer
+
+
+fun main() {
+     LibsodiumInitializer.initializeWithCallback {
+//        val hash = Hash.sha512("123".encodeToUByteArray())
+//        println("Hash (SHA512) of 123: ${hash.toHexString()}")
+         println("Hello")
+     }
+}

sample/src/wasmJsMain/resources/index.html

@@ -0,0 +1,12 @@
+<!doctype html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Libsodium bindings sample app!</title>
+    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">
+</head>
+<body>
+<div id="root"></div>
+<script src="sample.js"></script>
+</body>
+</html>