How can I use Gertty?

After getting a Gerrit API key (as explained in), use the basic auth-type in gertty.yaml, e.g.:

servers:
  - name: sftests
    url: https://sftests.com/r/a/
    git-url: ssh://USER_NAME@sftests.com:29418
    auth-type: basic
    username: USER_NAME
    password: API_KEY
    git-root: ~/git/