JSFiddle - React, Tailwind, and code Playground
HTML
<form>
<input type="email" id="1">
<br>
<input type="text" id="2" oninput="check(this)">
<br>
<button type="submit">submit</button>
</form>
CSS
input:invalid {
border: 1px solid red;
}
JavaScript
function check(input) {
if (input.value !== document.getElementById('1').value) {
input.setCustomValidity('Email Must be Matching.');
} else {
input.setCustomValidity('');
}
}