Method for creating a unique reference number

ref.vue

<template>
  <div>
  	<p>Reference Number: {{referenceNumber}}
  </div>
</template>

<script>
    export default {
        data: function () {
            return {
                referenceNumber: ''
            }
        },
		
		created () {
			this.refNumber();
		}
            
        methods: {
            refNumber: function () {
                let length = 12
                let timestamp = new Date().getTime();

                let _getRandInt = function (min, max) {
                    return Math.floor(Math.random() * (max - min + 1)) + min;
                }

                let generate = function () {
                    let ts = timestamp.toString();
                    let parts = ts.split('').reverse();
                    let ref = '';

                    for (let i = 0; i < length; ++i) {
                        let index = _getRandInt(0, parts.length - 1);
                        ref += parts[index];
                    }

                    return ref;
                }

                this.referenceNumber = generate();
            },
        }
    }
</script>