Symptoms
When inserting a YubiKey into your Mac's USB port, the Keyboard Setup Assistant opens.
Cause
To allow the YubiKey to be compatible across multiple hardware platforms and operating systems, the YubiKey appears as a USB keyboard to the operating system. The first time you insert a YubiKey, the Keyboard Setup Assistant may open.
Resolution
No action is necessary. Simply close the Keyboard Setup Assistant.
For more details, please visit Yubico's support website at https://support.yubico.com/hc/en-us/articles/360013790279.
Outcome
You can use your YubiKey for multifactor authentication.