Need help to generate OTP key for with Nitrokey 3

Hi, I want to use my Nitrokey 3A NFC to authenticate on via OTP. I found this solution by another user and I’m trying to repeat the steps. So the post says:

How do I generate a key? I’m used to touching the button on my Yubikey to generate an OTP, but with the Nitrokey, that doesn’t seem to work. Do I need the Nitrokey app?

I have installed the latest firmware version. My operating system is Linux Mint, if that matters.