I would think that card would probably work but I’d check in the Fast Channels Topic for recommendations because I have no experience with them. I use a Link Pi 5 port video encoder with Firestick 4K Max's. You’ll need one of those or an ONN stick to plug into. If you get a Firestick, make sure it's a 4K Max. The newer sticks have a different OS that's not compatible.
Fast Channels also has TVE options.
I'm using the Android Bridge under FastChannels with a cheap capture card and a 3rd Gen Firestick HD (not 4K). Works fine.
I can watch a channel in the Prismcast test window but get this error when I try to add Prismcast as a source in Channels: failed to load m3u: Get "http://localhost:5589/playlist": dial tcp [::1]:5589: connect: connection refused
Is this related to my router or tailscape (which I recently installed)?
guessing your prismcast isn't on same host/server as "localhost" .. you should always use your LAN ip there instead.