Make it so you can update the host to use sandbox.

[camspanos]

Remove the hardcoded const. The config already has the host set. Now we can use the setHost method to switch to sandbox host.

Now you can set the host to sandbox like this with the configuration:

$this->configuration = new Configuration([
    'clientId' => $clientId,
    'clientSecret' => $clientSecret,
]);
$this->configuration->setHost('https://sandbox.walmartapis.com');