Generate 5 unique numbers between 0-15 (Kotlin)

var questionToShow = arrayOfNulls<Int>(5)
fun main() {


    for (i in 0..4) {
          generateRandomInt(i)
    }
    for(e in questionToShow){
        println("Randoms in Array: $e")
    }
}

fun generateRandomInt(i:Int){
    val randomNumber = (0..14).random()

    if(questionToShow.contains(randomNumber)){
        println("Already Exist")
        println("Repeated: $randomNumber")

        //generate a random again
        generateRandomInt(i)

    }
    else{
        questionToShow[i] = randomNumber
        println("Random: $randomNumber")
    }
}