JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text"  id="inp_1">
<button onclick="multi()" >Жмакай</button>
Рeзультат: <span id="result_multi"></span>

JavaScript

function multi(){
    var multi_1;
	multi_1 = document.getElementById('inp_1').value;
	document.getElementById('result_multi').innerHTML = multi_1;
}