Upload the world zip to a file upload website. If your world is smaller than 100mb you can use file.io, otherwise we recommend you use Dropbox. [500mb Limit]
Get the direct download link to the file. If you're using Dropbox you can get the share link, but you need to replace ?dl=0 with ?dl=1 at the end of the link. If you're using file.io remember that the download links can only be used once.
Run the command /ul world <worldname> <direct link> in your server. Curtesy of the Minehut Discord Bot
More Info: