Damage NPC HELP

Can you help me with this code? The problem is that I want to make the NPC entity harmless when a player touches it and I want it to execute a command or a function

public function Damage(EntityDamageEvent $event){
$player = $event->getEntity();
if($player instanceof EntityDamageByEntityEvent){
$dama = $event->getDamager();
if($player instanceof Human && $dama instanceof Player){
$event->setCancelled();
$player = $event->getEntity();
if($player->getNameTag() === "§7§l≥§e FFA§7 ≤§r\n§aTap to play"){

 

Just copy the code from Slapper plugin on github

 

btw $player is not an Event