Macbook air to firewire?

Use a FireWire to Thunderbolt adapter and a Thunderbolt to Thunderbolt 3 adapter.

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Keep in mind that not all devices may be compatible with your M1 Mac. I was recently assisting another user trying to connect old Firewire drives in this manner using the Apple adapters suggested by @Neil, and it was not working. At least with old hard drives it is possible to remove them from their enclosures and connect them with newer adapters/enclosures.

Unfortunately there is no way to know which devices are compatible until you try them. I even had a newer USB-C device which works perfectly fine on an Intel Mac, but refuses to function on an M1 Mac even though both systems are running the same version of macOS.