Validate email in Contact form DB

Hello.

Previously I used ContactForm7, but decided to move to Fast Secure Contact Form.

Can you please help me with a hook to check if we already have person email in DB (Contact Form DB).

In CF7 I used this one, but don’t know how to update it for FS contact form:

function is_already_submitted($formName, $fieldName, $fieldValue){
    require_once(ABSPATH . 'wp-content/plugins/contact-form-7-to-database-extension/CFDBFormIterator.php');
    $exp = new CFDBFormIterator();
    $atts = array();
    $atts['show'] = $fieldName;
    $atts['filter'] = "$fieldName=$fieldValue";
    $exp->export($formName, $atts);
    $found = false;
    while ($row = $exp->nextRow()) {
        $found = true;
    }
    return $found;
}

function my_validate_email($result, $tag) {
    $formName = 'FORM_NAME'; // Name of the form containing this field
    $fieldName = 'WHAT_TO_CHECK'; // Set to your form's unique field name
    $name = $tag['name'];
    if($name == $fieldName){
        $valueToValidate = $_POST[$name];
        if (is_already_submitted($formName, $fieldName, $valueToValidate)) {
            $result->invalidate($name, 'Please, don't try to register twice.'); // error message
        }
    }
    return $result;
}

add_filter('wpcf7_validate_email*', 'my_validate_email', 10, 2);

https://www.ads-software.com/plugins/si-contact-form/