theres a thing called Uploadfiles.io https://uploadfiles.io

theres more though

you know in the drawing board there is a gear click that then at the to there is a download(red) and an upload(green). upload is a tool where when you have a file already (you need to download something first before you upload something) download is something where you have a drawing finished and you want to save it so press the one with the arrow pointing down and it downloads

yeah i´ll try to show you

here