How do you connect a camera that is SDI to a Mac so that it shows up as a video source in Camtasia?

I’m not sure if this is the right place but I’m asking here because I think this is going to take hardware.

I have a PTZ camera that is SDI and I need to get it to be a source in either Camtasia or OBS. I currently have the BlackMagic UltraStudio Mini Recorder hardware, but it’s not getting video. It’s just black. However it works with other cameras. So, is there some other hardware I can try?