ошибка при проксировании Mixed Content: The page at

Mixed Content: The page at 'https://www.example.com/store/account.htm' was loaded over HTTPS, but requested an insecure XMLHttpRequest endpoint 'http://www.example.com/isLogin.htm'. This request has been blocked; the content must be served over HTTPS.

        proxy_pass http://IIS;
      #  proxy_set_header Host example.ru;

        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Ssl on;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header      X-Forwarded-Proto https;