This package provides Mail.ru integration for OAuth2 Client by the League.
composer require aego/oauth2-mailru
$provider = new Aego\OAuth2\Client\Provider\Mailru([
'clientId' => '123456',
'clientSecret' => 'f23ccd066f8236c6f97a2a62d3f9f9f5',
'redirectUri' => 'https://example.org/oauth-endpoint',
]);