sc-controller is a snap which allows the Steam Controller to be used with non-Steam games. The upstream package does not run on modern Ubuntu releases as python2 has been deprecated and some libraries are unavailable. The snap gets around this problem by using the core18 packages.
Following lengthy discussion and analysis by the snapcraft and security team, such as @jdstrand, the uinput interface has been added to snapd to allow this application to function. As such, I would be grateful if the interface could be connected and authorised.