VK API returns erro 15, huh?

Question

JavaScript

trying to get url for later download

<script src="//vk.com/js/api/openapi.js" type="text/javascript"></script>

 function authInfo(response) {
        if (response.session) {
            VK.Api.call('photos.getWallUploadServer',
                    {
                        group_id: response.session.mid
                        v: 5.37
                    }, 
                    function (r) {
                        console.log(r);
 }
            )
            ;
        }
    }
    VK.Auth.getLoginStatus(authInfo);
    VK.UI.button('login_button');

which results in error 15 - "Access denied: no access to call this method".
Well, what does he need?