While you can easily add SFTP accounts and edit files using the explorer, There doesn't seem to be a way to use remote files for a project. You can specify the project as running on a remote server and various options of syncing a local directory to a remote server, but no way of just using the remote server without a local directory as an intermediate point for the files.

Depending on what sort of remote server you can choose to use for example Windows file shares and Samba on Linux. There are other methods available as well.

If it is a public server then you may decide to use firewall settings or tunnel/VPN & Samba over that to securely access remote files directly, but often something like SFTP is easier.

Nearly all of my development is done to remote servers with direct access to the remote files (no FTP), but I do not ever develop directly to public servers because I don't agree with it. Occasionally I might debug an issue on a public server, but you don't need direct access to the remote files to do that.