How to Yubikey
On Android, to unlock Keepass database secured with Yubikey, an alternative to Keepass2Android+ykdroid is KeePassDX[1] + Key Driver [2]. Both USB and NFC are supported.[1]: https://f-droid.org/en/packages/com.kunzisoft.keepass.libre/[2]: https://gitlab.com/kunzisoft/android-hardware-key-driver