It works you need a recent version of pynitro e.g. (v0.4.39). 1. Encode a secret using base32 e.g. using `echo "" | base32`. The resulting b32-secret-string needs to be exactly 20 bytes in length 2. ./nitropy-v0.4.39-x64-linux-binary nk3 secrets add-challenge-response {1,2} # There are two slots available 1 and 2 you need to choose one Afterwards you probably need to reboot the nitrokey e.g. by removing and reattaching it.