That's because you're working with an FTP server, not a remote shell server. For convenience, FTP's command set is similar to the standard command set, but the FTP shell isn't a command shell and it doesn't have all the command shell features.
The way to create an empty file on an FTP server is to upload an empty file to the FTP server. If your ftp client and local command shell permits it, that could include uploading an empty "here" file, but it's still got to be a file, even if it's only a temporary one.
An IDE is no substitute for an Intelligent Developer.