"Accessing npm using two-factor authentication" Guide's steps doesn't yield one-time password

I'm running into an issue while following this guide.

My goal is get npm working via the cli command line. Anytime I perform some action (for example trying to enable 2FA for auth-and-writes, or publishing a package, it asks me to "Enter one-time password:"

To my knowledge this is either a Security Key I made on my account on npmjs.com, or an authenticator app code--this of which I have no clue how to connect npm to my authenticator app in the first place and cannot find any resources.. As for the Security Key, when I follow step 4 in this guide "Click on Use security key and follow the browser specific steps to authenticate." this is what I see in my browser:

Okay good so far! But after I click on "Use security key" it displays this message:

This isn't what I was expecting. I was expecting to see my one-time password, which step 5 of the guide shows and asks me to copy:

Thus, I am at an impasse. I cannot get past this terminal message to use npm on the command line:

I am using Chrome on Mac. And I saved my Security Key via Keychain Access / Passwords mac app.

Start with the linked “Accessing npm using two-factor authentication” guide and compare its security-key steps with the CLI prompt described for enabling 2FA or publishing. Check whether the guide explains how authenticator-app codes are obtained and how security keys differ; done means the documented flow matches the observed browser and terminal behavior.