Require the cardholder name in Gravity Forms on your child site.
Snippet Type
Execute on Child Sites
Snippet
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 );