device add of Linux node using a Mac

I am attempting to add one of my Linux VMs to keybase, but when I go through the process to add the device it tells me to run keybase login on my other device. My other device is a mac, and when I run keybase login, the GUI pops up and it isn't immediately obvious to me from where I can get a verification code.

Reproduce adding a Linux VM as a device while running `keybase login` on macOS, starting with the macOS GUI flow described in the issue. Trace where the verification code is presented and make the code or its location obvious; done means a user can complete the device-add flow without guessing where to find it.

Written by the indexing model from the issue text.