How can I add a effect to a command?

What's here the mistake or what is another option to add an effect to an player for 600 seconds with amplification 4?

 

PHP:

$effect = Effect::getEffect(3);
$duration = 600 * 20; // times 20 because it's in ticks
$amplification = 4;
$effectInstance = new EffectInstance($effect, $duration, $amplification);
$player->addEffect($effectInstance);


 

u need to use :

PHP:

use pocketmine\entity\Effect;
use pocketmine\entity\EffectInstance;

and this code :

PHP:

$player->addEffect((new EffectInstance(Effect::getEffect(Effect::REGENERATION)))->setDuration(intval(20*600))->setAmplifier(intval(4)));