Jump Boost Player

Hey! I need help with my plugin. I dont know how to give the player a jump boost, if he stands on a sponge block! I tried already this:

PHP:

public function onMove(PlayerMoveEvent $event) {
        $player = $event->getPlayer();
        if($player->getLevel()->getFolderName() === "Testworld") {
            $block1 = $player->getLevel()->getBlock($player->floor()->subtract(0, 1));
            if($block1->getId() === Block::SPONGE) {
                $player->setMotion(new Vector3($player->getX(), $player->getY()+2, $player->getZ()));
            }
        }
    }

Can anyone help me or explain me how can I make that? :'D Thanks!!

Do:

PHP:

$player->setMotion($player->getMotion()->multiply($x));

Isn't ... ?

Code:

3 * 1 = 3

Try Entity::knockBack()

just use $player->knockBack();

knockBack($attacker, $damage, $x, $z) has not y, and I need y

there is another paramater called base i think, and depending on what u set it as the higher the player goes. Try something like knockback($damage, $x, $z, 0.10);

Simply use my method?