Do I need a capture card when streaming?

I wanted to start streaming on Twitch for fun and because of the Corona free time. I wanted to stream from my laptop, but I play on the PS4. I heard that you need a capture card for this, especially since I also want a face cam. Is this capture card necessary or are there other methods?

You can stream directly from the PS4. Capture Card only use a lot so that you can use some features of OBS.

Yes, the thing is, if I want to have a Facecam I need OBS

Yes if you use one over PC clearly. But if you don't want to spend money on an Elgato now, you should leave out the Facecam.

Many streamers and Youtubers use a so-called Avermedia box to record from consoles.

The box is connected between the console and the TV / monitor and records the picture and the game sound.
In addition, the Avermedia box is connected to the PC via mini-USB, after which the box saves the recording.

If you want to record the webcam, you have to record it separately with the PC.

https://smile.amazon.de/AVerMedia-Live-Gamer-Portable-Videoschnittkarte/dp/B00I0QZMPE/