whmcsCrosterTemplates/oauth/redirect.tpl

<div class="container">
    <div class="alert alert-success text-center">
        {lang key='oauth.redirectDescriptionOne'}<br />
        {lang key='oauth.redirectDescriptionTwo'}
        <a href="#" class="alert-link">
            {lang key='oauth.redirectDescriptionThree'}
            <i class="fas fa-arrow-right"></i>
        </a>
    </div>
</div>