Hello,
I just read this section of your good documentation. Can you please explain a bit in detail what are OTP secrets. And what exactly are passwords? Plain text strings? And the last question.
There is an option to add random data to the nk3 - nitropy nk3 rng. What does this mean and should I do so?
Regards. 
T.L.
Yes, passwords are just strings. OTP secrets are one-time passwords, typically TOTP, see Two-factor Authentication with One-Time Passwords (OTP) - Nitrokey Documentation. They can be used as a second factor similar to FIDO2.
nitropy nk3 rng does not add data to the Nitrokey, it provides random data backed by the hardware RNG of the Nitrokey. So you can use it for anything that requires random input.
