Error in Assigning MFA device (PASSKEY)

Hello.

Are you using a device or browser that is not supported as described in the documentation below?
Therefore, I think it is a good idea to first check whether the device is compatible and whether the browser can be used.
https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_mfa_fido_supported_configurations.html

Finally I forgot that documentation have been mentioned that "IAM does not support local passkey registration for Windows Hello. To create and use passkeys, Windows users should use cross-device authentication where you use a passkey from one device like a mobile device or hardware security key to sign in on another device like a laptop."

So you cannot register it by Windows Hello. Instead, I am using Yubikey 5C NFC for handling identity verification

The same as you, I am using Microsoft Edge (127.0.2651.8)