JSFiddle - React, Tailwind, and code Playground

by ahmadka

HTML

<form>
    <input type="email" id="email" placeholder="Enter your email here..." required>
    <button type="submit">Submit</button>
</form>
    
<button id="triggerMsg" onclick="triggerCustomMsg()">Trigger Custom Message</button>

JavaScript

function triggerCustomMsg()
{
    document.getElementById("email").setCustomValidity("This email is already used");
    
}