gform_gfcf_custom_empty_field_check

add_filter(  'gform_gfcf_custom_empty_field_check', 'your_function_name' );

add_filter( 'gform_pre_render', 'add_custom_gform_js_filters' );
function add_custom_gform_js_filters($form) {
    ?>
    <script type="text/javascript">
        document.addEventListener('DOMContentLoaded', function() {
            // Custom function to add to the gform_gfcf_custom_empty_field_check filter.
            function customBypassValidations(bypassFunctions) {
                // The pipe field is a hidden input element and, by default, hidden elements
                // arent counted as filled fields when checking if the form is empty.
                // Adding a filter for the pipe field will force Conversational Forms
                // to check if the field is empty or not.
                bypassFunctions.push( [
                    // check if the input is of pipe recorder
                    (input) => input.closest('.gfield--input-type-pipe_recorder'),
                    // set to false so internally is not bypassed as a hidden input
                    (input) => false
                ]);
                return bypassFunctions;
            }

            // Add filter to the gform object
            if(typeof gform !== 'undefined') gform.addFilter('gform_gfcf_custom_empty_field_check', customBypassValidations);
        });
    </script>
    <?php
    return $form;
}