The reverse image search is currently officially disabled by Taobao.
It looks like Taobao finally killed all workarounds. The reverse image search is officially dead :( You can try your luck with the legacy link below.
But there's a simple workaround to still use it. All you have to do is open a direct legacy link and then upload your own photo. Here's a direct link.
Once you're there using the reverse image search is really simple. You just click the camera icon and upload your own image.