Now you can connect to a remote desktop using Rust Desk, an open source AnyDesk clone written in Rust. It works with no configuration required except installation on both desktops. You have full control of your data and you can either use their server or self host your own. It also runs on Windows, Mac, Kubuntu, Android and iOS.
This is especially great for Kubuntu because although you can use KRDC to connect to Krfb it isn't very fast and using it outside your network means opening ports in your router. Rust Desk uses a server to negotiate between the two desktops. Either theirs or you can host your own with docker. Additionally you can alter the permissions of the connection, chat and transfer files.
My favourite feature though is that what I type on my computer comes out the same as the other computer. Some of my computers have QWERTY and some have AZERTY and not having to remember AZERTY on a QWERTY keyboard is a god send. It isn't perfect, some special characters don't work but it is a lot easier than Krfb.
To install Rust Desk you need to install it on both computers. Download the executable for each operating system from the website.
Install on both desktops and then from one machine application input the ID of the other machine application under "Control Remote Desktop" and they will start connecting. You will also be asked for a password which can be found under the ID on each application. It is eight characters long which seemed a little short to me as a default but you can edit it and input your own.