JSFiddle - React, Tailwind, and code Playground
HTML
<input type="username" value="test">
<input type="text" id="user" name="user" onblur="userExist()">
JavaScript
console.log($("input[type=username]").val());
<input type="username" value="test">
<input type="text" id="user" name="user" onblur="userExist()">
console.log($("input[type=username]").val());