did you bother to look at @snippsat image? He shows with arrow the Upload that you need to use. How you will see the file before you upload it?
If you can't explain it to a six year old, you don't understand it yourself, Albert Einstein
How to Ask Questions The Smart Way: link and another link
Create MCV example
Debug small programs
How to Ask Questions The Smart Way: link and another link
Create MCV example
Debug small programs