Hello! @phenders
Welcome to the LastPass Community.
Unfortunately, we do not offer a log in using a passkey since the session is close there is no way for LastPass to save the passkey outside of the vault, but we do offer you password less log in where you can use the LastPass MFA app to log in or your finger print in case prefer, go to your vault, account settings, password less log in.
Please let me know if you need additional help.
Greetings!
Verlaine | Customer Care