Lets Start .. xd
open google.com and enter this dork : "intext:File Upload by Encodable"
result comes with 166,000 results but some results are fake ... its may be malwaers
so pick real things only , "Upload a file" You will this title in search results here :)
click the sites sites only which comes with upload a file title
after click the link you'll got a upload form
you'll saw some options in this form like name Description email etc ...
type anything in these boxes but add a email in email box, dont use your own
put this one billy@microsoft.com , admin@nasa.gov etc :P
now choose you file and upload it :)
after clicking on upload button a pop up will be open ... dont close it, it will automatilcly closed
after uploading file
in some sites you'll got you uploaded file link after uploading on website
and if you did not file it then try these url
/upload/files/
or /upload/userfiles/
Live Demo : http://150.101.230.65:8008/cgi-bin/filechucker.plx
Uploaded page : http://150.101.230.65:8008/upload/files/xd.html