Drulabel only runs on git.drupalcode.org, and only talks to
git.drupalcode.org:

• It reads the issue, the project's labels, branches and tags, the issue's
  links and its issue fork through GitLab's APIs, using your existing login
  if you have one. These are the same requests GitLab's own pages make.
• It doesn't store anything, and doesn't send anything to any other server.
  There are no analytics or tracking.
• It never posts anything itself. It only adds commands to the comment box,
  or to the clipboard when you click Copy, and you decide whether to
  submit them.
• If the comment box is in rich text mode, Add to comment clicks GitLab's
  own switch to Markdown mode. GitLab remembers that choice for your account,
  as it would if you had clicked it yourself.