JSFiddle - React, Tailwind, and code Playground

HTML

<button id="change" onClick="document.getElementById('btnChoice1').setAttribute('class', 'redButton');">change</button>
<button class="basicButton" id="btnChoice1">
    test
</button>

CSS

.basicButton {
    width:300px;
}

.redButton {
    width:300px;
    background-color:red;
}