Code-Snippets-Functions/Execute a function on a child site/Gravity Forms/require-cardholder-name.txt

add_filter( 'gform_field_validation', function ( $result, $value, $form, $field ) {
    if ( $field->type == 'creditcard' && $result['is_valid'] && rgempty( $field->id . '.5', $value ) ) {
        $result['is_valid'] = false;
        $result['message']  = 'Please enter the cardholder first and last name.';
    }
 
    return $result;
}, 10, 4 );