I built off of Derek’s answer because I needed to use the built in landing pages, I was not using the form embed. The following worked for me.
<script>
//code for redirecting to brew ninja signup flow after they enter their email
$(document).ready(function() {
setTimeout(function() {
var form = $('[data-form-id=xxx-xxx-xx-your-form-id]');
form.submit(function() {
var email = $('[data-form-id=xxx-xxx-xx-your-form-id]').find('[name=email]').val();
setTimeout(function() {
window.location.href = 'https://yoursite.com?email=' + email;
}, 500);
});
}, 500);
});
</script>