Config error?

I made if player someone dies, remove player's name from Yaml. but it doesn't work.

Code:

$p = $this->Pist->getAll();

    $config = new Config("Pist.yml", Config::YAML);

    $DeadPlayer = $Die->getPlayer()->getName();

    $config->remove("{$DeadPlayer}");

    $this->Pist->setAll($p);
    $this->Pist->save();

ErrorException: "yaml_parse(): scanning error encountered during parsing: mapping values are not allowed in this context (line 2, column 7)" (EXCEPTION) in "src/pocketmine/utils/Config" at line 185

 

Please https://forums.pmmp.io/threads/using-configs.1975/