Provider.php

<?php

namespace SocialiteProviders\Zalo;

use GuzzleHttp\RequestOptions;
use SocialiteProviders\Manager\OAuth2\AbstractProvider;
use SocialiteProviders\Manager\OAuth2\User;

class Provider extends AbstractProvider
{
    public const IDENTIFIER = 'ZALO';

    /**
     * {@inheritdoc}
     */
    protected function getAuthUrl($state)
    {
        return $this->buildAuthUrlFromBase('https://oauth.zaloapp.com/v4/permission', $state);
    }

    /**
     * {@inheritdoc}
     */
    protected function getCodeFields($state = null)
    {
        $fields = parent::getCodeFields($state);

        $fields['app_id'] = $this->clientId;

        return $fields;
    }

    /**
     * {@inheritdoc}
     */
    public function getAccessTokenResponse($code)
    {
        $response = $this->getHttpClient()->post($this->getTokenUrl(), [
            RequestOptions::HEADERS     => ['secret_key' => $this->clientSecret],
            RequestOptions::FORM_PARAMS => $this->getTokenFields($code),
        ]);

        return json_decode((string) $response->getBody(), true);
    }

    /**
     * {@inheritdoc}
     */
    protected function getTokenUrl()
    {
        return 'https://oauth.zaloapp.com/v4/access_token';
    }

    /**
     * {@inheritdoc}
     */
    protected function getUserByToken($token)
    {
        $response = $this->getHttpClient()->get('https://graph.zalo.me/v2.0/me', [
            RequestOptions::HEADERS => ['access_token' => $token],
            RequestOptions::QUERY   => ['fields' => 'id,error,message,name,picture'],
        ]);

        return json_decode((string) $response->getBody(), true);
    }

    /**
     * {@inheritdoc}
     */
    protected function mapUserToObject(array $user)
    {
        return (new User)->setRaw($user)->map([
            'id'       => $user['id'],
            'nickname' => null,
            'name'     => $user['name'] ?? null,
            'avatar'   => preg_replace('/^http:/i', 'https:', $user['picture']['data']['url']),
        ]);
    }

    /**
     * {@inheritdoc}
     */
    protected function getTokenFields($code)
    {
        return array_merge(parent::getTokenFields($code), [
            'app_id' => $this->clientId,
        ]);
    }
}