Authorization required: sitemap.xml
Verification word: backboard

Approve on your phone -- open or scan this on a device with your passkey:
  https://auth.ck1.me/a/eyJhbGciOiJIUzI1NiJ9.eyJyZXMiOnsidHlwZSI6Im9iamVjdCIsImlkIjoic2l0ZW1hcC54bWwifSwid29yZCI6ImJhY2tib2FyZCIsImp0aSI6IjE0NjY1ZDlmOWEyYTRhYzJhODZlNGM0Nzk3NjE0ZDJmIiwiaXNzIjoic2VydmVzLmNrMS5tZSIsImF1ZCI6ImF1dGguY2sxLm1lIiwiaWF0IjoxNzg0OTE4MDI5LCJleHAiOjE3ODQ5MTgzMjl9.uo-WgW9UtAxYqjNlA0_2YkZztIYpfBKUOQPTPd4-cgY

(No browser on this box? Cmd-click that link to open it on your laptop;
 it shows a QR you can scan with your phone.)

Then fetch the file -- this command waits until you approve:
  curl -fL 'https://serves.ck1.me/sitemap.xml?grant=eyJhbGciOiJIUzI1NiJ9.eyJyZXMiOnsidHlwZSI6Im9iamVjdCIsImlkIjoic2l0ZW1hcC54bWwifSwid29yZCI6ImJhY2tib2FyZCIsImp0aSI6IjE0NjY1ZDlmOWEyYTRhYzJhODZlNGM0Nzk3NjE0ZDJmIiwiaXNzIjoic2VydmVzLmNrMS5tZSIsImF1ZCI6ImF1dGguY2sxLm1lIiwiaWF0IjoxNzg0OTE4MDI5LCJleHAiOjE3ODQ5MTgzMjl9.uo-WgW9UtAxYqjNlA0_2YkZztIYpfBKUOQPTPd4-cgY' -o 'sitemap.xml'