Using Glyphicons icons

<!-- Put them in the head tag -->
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.4.1/css/bootstrap.min.css" />
<link rel="stylesheet" href="/vendors/@form-validation/umd/styles/index.min.css" />

<form id="demoForm">...</form>

<script src="/vendors/@form-validation/umd/bundle/popular.min.js"></script>
<script src="/vendors/@form-validation/umd/plugin-bootstrap3/index.min.js"></script>

<script>
    document.addEventListener('DOMContentLoaded', function(e) {
        FormValidation.formValidation(
            document.getElementById('demoForm'),
            {
                fields: {
                    ...
                },
                plugins: {
                    bootstrap3: new FormValidation.plugins.Bootstrap3(),
                    icon: new FormValidation.plugins.Icon({
                        valid: 'glyphicon glyphicon-ok',
                        invalid: 'glyphicon glyphicon-remove',
                        validating: 'glyphicon glyphicon-refresh',
                    }),
                },
            }
        );
    });
</script>