How to record your real-time compositing?


I have a setup for virtual production that I’m pretty content with but I struggle when it comes to saving the footage. Unfortunately I don’t have a BlackMagic capture card and I wanted to explore other ways but I’m struggling to find any information. I usually set the output of the Composition to Player Viewport so that I can directly see the end result. I tried setting it to MediaSource->FileMediaOutput but nothing gets saved after Playing in editor. Do I have to start recording in some other way?
I guess I can use Media Capture to create a bunch of EXR files but I was wondering if there are some other options.