How to force/set Fido2 capabilities for PC/Browser?

While playing around with my Nitrokey 3 NFC i found out the following behavior with the bitwarden website.

  1. If i add the Nitrokey on a PC for webauth as a 2nd factor using Firefox, it requests me to enter the Fido2 PIN and adds a resident key, taking up one of the valuable keyslots.
    1.1 Logging in on the account on PC via USB requires me to enter the PIN and touch. Login works
    1.2 Logging in on the account via Anroid phone and NFC doesnt work. No PIN entry field is displayed and access is denied.

  2. If i add the same nitrokey on my Android phone using Firefox, no PIN is required to add it. No resident key slot is taken up
    2.1 Logging in PC works with just touching the key.
    2.2 Logging in on Phone works with just reading the key by NFC

TLDR i want to decide which capabilities are presented to firefox, so that i dont need to go through setting up my key as a 2nd factor through my phone, to actually be able to use it on my phone and/or control what is using up my resident key slots. How can i do that?

Thank you for reading!


i found out a working solution. But would still like to know if there is anything better.

Solution: go to about:config in firefox and turn off the key “security.webauthn.ctap2”. Behaviour is then like on Android. On setup, only a tap on the key is requested and the key works also via NFC at the phone.