public function getAuthorizationUrl() 
    {
        $result = null;
        if (!$this->config->hasCredentials()) {
            $this->registerApplication();
        }
        //Return the Authorization URL
        return "https://{$this->config->getMastodonInstance()}/oauth/authorize/?".http_build_query(
            [
            "response_type"    => "code",
            // @todo review usage of singular / plural in redirect_uri
            "redirect_uri"     => $this->config->getRedirectUris(),
            "scope"            => $this->config->getScopes(),
            "client_id"        => $this->config->getClientId(),
            ]
        );
    }