Plex does not recognise my TV tuner

I have Plex on my iMac and have added a TVButler UBS tuner. The tuner is not being recognised by my Plex and I wonder if I need to buy a pass before it does so?

Soz, I meant USB but I’m sure you all knew that!

Plex Pass required.

Supported DVR Tuners and Antennas
https://support.plex.tv/articles/225877427-supported-dvr-tuners-and-antennas/

Tip!: Setting up and using a DVR or Live TV is a premium feature and requires an active Plex Pass subscription.