plugin code not working, need help

I'm working on a simple plugin which just tells the user if they are op or not when they type the command, but it is not working as when I typed the command nothing happened, can anyone help me please

this is my code:

<?php
namespace SSLukeY\showRank;
use pocketmine\plugin\PluginBase;
use pocketmine\Player;
use pocketmine\command\Command;
use pocketmine\command\CommandSender;

class main extends PluginBase{
public function onCommand(CommandSender $sender, Command $command, $label, array $args) {
if (strtolower($command->getName("myrank"))) {
if ($sender instanceof Player) {
if ($sender-isOP()) {
$sender->sendMessage("yes");
}
if ($sender->isOP() == false) {
$sender->sendMessage("no");
}
}
}
}
}

this is my yml file:
name: showRank
version: 1.0.0
main: SSLukeY\showRank\main
api: 1.0.0
commands:
myrank:
description: show if you are a op or not

Try to read your code again next time, it's must be:
1. $sender->isOp() not $sender-isOP()

PHP:

if($sender instanceof Player) {
  if($sender->isOp()) {
     $sender->sendMessage("Yes");
    }
}

2. Try to use

PHP:

if(($command->getName()) == "myrank") {

3. Use else

PHP:

if($sender->isOp()) {
       $sender->sendMessage("Yes");
 } else {
     $sender->sendMessage("No");
}

3. Remeber, plugin.yml is YML, so don't forget to space

Also, use api 2.0.0

PHP:

 If (strtolower ($command->getName ()) == "myrank"){ 

@JonsMC $sender->isOp () and $sender->isOP() they two are working too

Use

PHP:

if($command->getName() === "myrank")

Also... This would work too

PHP:

$sender->sendMessage($sender->isOp() ? "Yes" : "No");

You also forgot the ">" at the first if statement.

PluginBase :: onCommand requires bool value to be returned. If it's a false, then usage message will be shown else not.

Next time attach an error string.