Having trouble setting custom endpoints for Hybridauth provider (WordPress)

I'm trying to use Hybridauth (ver 3) to get a list of an authenticated user's WordPress blogs, using the https://public-api.wordpress.com/rest/v1.1/me/sites endpoint. Figured out that in order to do so, I need to change the default authorize_url endpoint for WordPress from https://public-api.wordpress.com/oauth2/authenticate to https://public-api.wordpress.com/oauth2/authorize.

Hybridauth lets you change the endpoint, as in this example here: https://github.com/hybridauth/hybridauth/blob/master/examples/example_03.php

Unfortunately, this results in the following error:

Fatal error: Uncaught TypeError: Argument 1 passed to Hybridauth\Adapter\AbstractAdapter::setApiEndpoints() must be an instance of Hybridauth\Data\Collection, array given

The code:

$config = [
    "callback"      => APP_URL."/callback", 
    "keys"          => array("id" => "XXXXXX", "secret" => "YYYYYYYYYY"),
    "scope"         => array("global", "auth"),
    "endpoints"     => [
        "authorize_url"    => "https://public-api.wordpress.com/oauth2/authorize",
    ]
];

$adapter = new Hybridauth\Provider\WordPress($config);

What am I doing wrong? I feel like I'm missing out on something horribly obvious.

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