JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="txtTotal">
<br>
<input type="button" id="btnSend" value="Save the total"> <input type="button" id="btnLastTotal" value="get Last Total">

JavaScript

document.getElementById('btnSend').onclick = ()=>{
let total = document.getElementById('txtTotal').value;
if(!isNaN(total)){
localStorage.setItem('total', total);
document.getElementById('txtTotal').value = '';
}
}
document.getElementById('btnLastTotal').onclick = ()=>{
var lastTotal = localStorage.getItem('total');
if(lastTotal !=undefined){
alert('last total is:'+lastTotal);
}else{
alert('No records found');
}
}