How to solve Undefined index

Here is code

PHP:

$Health = $this->GO["MaxHealth"]["$Players"];

and when I run it, It says [Server thread/CRITICAL]: ErrorException: "Undefined index: MaxHealth" (EXCEPTION)

And I wrote this code in onEnable()

PHP:

$this->GOO = new Config ($this->getDataFolder()."GO.yml",Config::YAML);
            $this->GO = $this->GOO->getAll();

How can I solve this problem?

 

Your config does not have the key MaxHealth

 

Is there only a way to write MaxHealth already in this?

PHP:

$this->GOO = new Config ($this->getDataFolder()."GO.yml",Config::YAML);
            $this->GO = $this->GOO->getAll();

If is right, how can I write already?

 

PHP:

$this->GOO = (new Config($this->getDataFolder() . "GO.yml", Config::YAML, array(
    "Max-Health" => "yourvalue",
)));
$this->GO = $this->GOO->getAll();

Try this, i think it works, im ln mobile rn so idrk

 

or u can do

PHP:

$this->GOO = new Config($this->getDataFolder() . "GO.yml", Config::YAML);
$this->GOO->set("Max-Health", 1); //u can change 1 to whatever int value you want
$this->GO = $this->GOO->getAll();