Pls help :-:

So I found my old elgato in my closet so I decided to hook it up for the first time in awhile and I’m running into an issue. I didn’t have the original usb that you connect to your pc from the elgato itself so I found one hooked it up and seems to be working (I’m thinking it might be the issue) after I watched a video on how to set it up my tv acts like there is a hdmi connection and will pop up but on my game capture hd software it keeps on telling me to connect my device which I find strange since when I unplug the usb my tv goes black as the same for the hdmi cables so I’m just at a loss right now and YouTube and google isn’t helping and only showing me tips on how to fix a black screen so any help would be greatly appreciated ❤️❤️