That feature was only available for the premium dropbox users, but was discontinued, because "insert dropbox logic".
But now a days, you can get a free webhosting a free domain and upload your files there and server them to people you want. Wix is a good place to start for free, there are other services as well, like freehosting , 000webhost (this might cause some security issues, but not big concerning), hostinger, etc.