Installing #Authnkey from #fdroid got my #Yubikey to work via NFC on #GrapheneOS

https://github.com/mimi89999/Authnkey

"Android's built-in #WebAuthn support has a significant gap: it does not support #CTAP2 over NFC. This means you cannot use PIN-protected passkeys or discoverable credentials with NFC
... Authnkey fills this gap by implementing the full CTAP2 protocol."