I want to upload the local folder with Github only (without using Git)

There seems to be no way to create only empty folders, so please try to create an empty file by following the steps below.
The Create new file on the top screen of the repository moves to the new file creation screen, so it seems that the folder will be created automatically if you separate it with / in the file name entry field.

Note:
Creating new folders in GitHub repository via the browser

Similar questions in English stack overflow are helpful.

You can create a file in a new folder by using / (slash) as the file name in the Create File interface.The link is in English, but there is a video, so you will know how to do it.

One thing to note is that this way you can create a folder and create a file in it at the same time.This is an inevitable constraint because git does not handle empty folders.