Using an iPhone as FIDO2 hardware token?

There are many FIDO2 security hardware tokens on the market that allow password-less login on web sites e.g. on your PC. For example from YubiKey, FEITIAN, ePass... These token communicate for example via NFC with the PC. But I don't want to use an extra token, when I have my iPhone which could do the job as well. Is it possible to use an iPhone as a FIDO2 hardware token instead of those tiny hardware FIDO2 tokens? Is this possible with a plain iPhone running iOS 14.6 or do I need a special app so that the iPhone could act as authenticator? I am aware that this would not work for authentication of web site in Safari on the iPhone, I only want the iPhone for FIDO2 authentication of my PC.