Spawn an entity

Where is the mistake?

ArgumentCountError: "Too few arguments to function NiLen\NPC\NPC::npc6(), 1 passed in /srv/data/plugins/NPC_plugin/src/NiLen/NPC/NPC.php on line 76 and exactly 2 expected

public function npc6($type, Player $player){
$nbt = new CompoundTag("", [
"Pos" => new ListTag("Pos", [
new DoubleTag ("", $player->x),
new DoubleTag ("", $player->y + $player->getEyeHeight()),
new DoubleTag ("", $player->z)
]),
"Motion" => new ListTag("Motion", [
new DoubleTag("", 0),
new DoubleTag("", 0),
new DoubleTag("", 0)
]),
"Rotation" => new ListTag("Rotation", [
new FloatTag ("", $player->yaw),
new FloatTag ("", $player->pitch)
]),
]);

$snowball = Entity::createEntity("Cow", $player->getLevel(), $type, $nbt);


$snowball->spawnToAll(true);
}

Spawn code:

$this->npc6($player);

 

PHP:

public function npc6(Player $player){
                            $nbt = new CompoundTag("", [
                                "Pos" => new ListTag("Pos", [
                                new DoubleTag ("", $player->x),
                                new DoubleTag ("", $player->y + $player->getEyeHeight()),
                                new DoubleTag ("", $player->z)
                                ]),
                                "Motion" => new ListTag("Motion", [
                                new DoubleTag("", 0),
                                new DoubleTag("", 0),
                                new DoubleTag("", 0)
                                ]),
                                "Rotation" => new ListTag("Rotation", [
                                new FloatTag ("", $player->yaw),
                                new FloatTag ("", $player->pitch)
                            ]),
                                ]);
              
                                $snowball = Entity::createEntity("Cow", $player->getLevel(), $type, $nbt);
                              
                              
                $snowball->spawnToAll(true);
                                }



 

new mistake:
Error: "Call to a member function spawnToAll() on null" (EXCEPTION) in "plugins/NPC_plugin/src/NiLen/NPC/NPC" at line 213
[13:28:47] [Server thread/CRITICAL]: #0 plugins/NPC_plugin/src/NiLen/NPC/NPC(76): NiLen\NPC\NPC->npc6(object pocketmine\Player)

 

You need to register the Cow entity

 

how to register this entity?

 

https://forums.pmmp.io/threads/spawning-an-entity.6477/#post-55854

 

Thanks

 

I did it exactly the same but it does not work

ReflectionException: "Class NiLen\NPC\Cow does not exist" (-1) in "pmsrc/src/pocketmine/entity/Entity" at line 399

The line with this error:
Entity::registerEntity(Сow::class);

 

you need to implement the cow entity