i tried to use data flag riding but nothing happens :/ is it working? PHP: if($sender instanceof Player){ $sender->setDataFlag(Entity::DATA_FLAGS, Entity::DATA_FLAG_RIDING, true);}
and please how did you make sound when player join on your server? is it one of this sounds? (bat, click, door, fizz, launch, pop)
Surf into PocketMine-MP API and look for how things work, for sound its pretty easy: $level->addSound(Sound instance) For riding flag, it just show other players that the current one is "riding", but nothing more will happen unless your code Make it
The data flag is only to show to other players that that player is riding, but to that player he is still standing. Extra work needs to be done to support riding fully. https://github.com/PocketMine/PocketMine-MP/compare/riding-work