Django在文件上传中引发MultiValueDictKeyError

I have already consulted lots of forums and I can't get an answer. I have installed a file upload in my Django app to save data into my server. But it does not work. Instead, it raises a MultiValueDictKeyError. I guess the problem is that there is not request.FILES (because it raises an error in request.FILES mentions), so the file upload is not working. This is my views.py:I have already consulted lots of forums and I c