JSFiddle - React, Tailwind, and code Playground

JavaScript

function randomInteger(min, max) {
    var rand = min + Math.random() * (max + 1 - min);
    rand = Math.floor(rand);
    return rand;
}

function randomSet(n) {
  var str = '0123456789',
      num = '';

  for (var i = 0; i < n; i++) {
    var j = randomInteger(0, str.length - 1);
    num += str[j]
    str = str.slice(0, j) + str.slice(j+1);
  }
  return num;
}

console.log(randomSet(1));
console.log(randomSet(2));
console.log(randomSet(3));
console.log(randomSet(4));
console.log(randomSet(4));
console.log(randomSet(5));
console.log(randomSet(6));
console.log(randomSet(7));
console.log(randomSet(8));
console.log(randomSet(9));
console.log(randomSet(10));