Solved Instance of Player in world

How do i get instance of player in a world ex. If player enters a command the code gets the player's world name if his in a world named spawn the command will work

 

PHP:

public function onCommand(CommandSender $sender, Command $cmd, $label, array $args) {
    if($sender->getLevel()->getName() === "spawn") {
        if($cmd->getName() === "blablabla") {
            // code here
        }
    }
}


 

Thanks