JSFiddle - React, Tailwind, and code Playground

HTML

<input type='text' value='Hello World!' id='txtbox' />
<br />
<button id="btnSelect">select text</button>
<button id="btnRemove">remove selected text</button>

JavaScript

$("#btnSelect").click(function () {
    document.getElementById('txtbox').setSelectionRange(6, 12);
});
$("#btnRemove").click(function () {
    var ele  = document.getElementById('txtbox');
    var text = ele.value;
    
    text = text.slice(0, ele.selectionStart) + text.slice(ele.selectionEnd);
    ele.value = text;
});