THERE IS NO FIREWIRE TO USB CABLE. THERE NEVER HAS BEEN!

Let's not go over that again.

For a desktop PC you add a Firewire card and done. 10 to 20 bucks:
https://www.newegg.com/Product/ProductList.aspx?Description=firewire%20PCIe&Submit=ENE

For laptops it's best to forget it and use another desktop with that card or a laptop with firewire as the old thing that used to do this is rare. So rare that we may as well hunt unicorns. It is no more.