Yubico has a nice tool to test the process of using passkeys. Try it out at the following link:

https://passkey.org/

How to use tool:

1. Create a test username, if it is not available try a different username.
2. Click continue.
3. You will be prompted to create a passkey.
4. Once you enter your system credentials, a passkey will be created.
5. Click sign out.
6. To test the passkey, click "Sign in with passkey."
7. Your device will prompt to use a passkey. Click continue.