It is important to note that you do not want to lose your electronic key. Apple will prompt you to set up two to begin with so you can keep the backup in a safe place. But if you somehow lose both of them, chances are your account will be permanently locked out (there may be recovery options, but Apple doesn’t specify what that is, perhaps for security reasons).
You also need to follow this process when signing into your Apple ID in a new web browser, and there are a few places where it won’t work (at least not yet). Perhaps the most important of these is iCloud for Windows, so you might want to refrain if using your Apple account on Windows devices. And you can’t use security keys with Apple devices with older software or Apple IDs assigned to children.
Setting up electronic keys
The first step is to buy a pair of security keys, which cost about $50 each online. Apple says you need keys certified to work with the FIDO (Fast ID Online) standard and with the correct connections for your devices: NFC (iPhone), Lightning, USB-C or USB-A only. You can use adapters and cables with these security keys, which should make it easier to find keys that work with whatever you’re going to use.
With your physical keys in hand and the latest software updates installed, you can set everything up from your iPhone or iPad by going to Settings, tapping on your name at the top, and selecting password and safety. Choose Add electronic keys be guided through the process of linking them to your Apple ID. At the same time, you can view all devices that are currently associated with your Apple ID.
On macOS, make sure you have the latest software, then open Apple menu and choose System settings. Click your name at the top of the navigation bar on the left, then select password and safety and press Add next to the heading Electronic Keys. You will then follow the steps required to link your keys to your account and you will be shown the devices you are already using with your Apple ID.
You need to add at least two security keys to your account, as we mentioned earlier, and you can add up to six. Go to the same screens in iOS, iPadOS or macOS if you want to remove one or more security keys – you will see Delete all dongles option. If you choose this, the two-factor authentication process will revert to using the password method as it was before.