JSFiddle - React, Tailwind, and code Playground

HTML

<input type="datetime-local" name="name" id="1234">

JavaScript

Number.prototype.AddZero= function(b,c){
            var  l= (String(b|| 10).length - String(this).length)+1;
            return l> 0? new Array(l).join(c|| '0')+this : this;
         }//to add zero to less than 10,
         
         
           var d = new Date(),
           localDateTime= [(d.getMonth()+1).AddZero(),
                    d.getDate().AddZero(),
                    d.getFullYear()].join('/') +', ' +
                   [d.getHours().AddZero(),
                    d.getMinutes().AddZero()].join(':');
           var elem=document.getElementById("1234"); 
           elem.value = localDateTime;