a phone pointing at the tv is the least you need. want better quality and youll need a composite capture card

I use the Elgato Game capture not sure if you can buy it anymore but I would use a capture card from Elgato or something like that

For the best results, use a retrotink to upscale the image and capture it was an HDMI capture card, preferably an internal PCIe Card. You can choose from AverMedia, Elgato or Blackmagic, depending on what you are looking for. Elgato is pretty much only worth it if they are on sale as they are overpriced, the other cards are very solid but a blackmagic intensity pro costs quite a lot of money. That one is compatible tho with retro signals.