LINE MAN Wongnai Mysterious Code - https://github.com/LINEMANWongnai/LINE-MAN-Wongnai-Mysterious-Code

lmwn.kt

import java.util.Base64

fun main() {
    val secret = "aWFuZ25vVzpOQU06RU5JTDp0YTpzdTpuaW9K"
    val mysteriousCode  = String(Base64.getDecoder().decode(secret)).reversed()
    println("Mysterious Code: $mysteriousCode")
}