Authorization required: sitemap.xml
Verification word: slurp

Approve on your phone -- open or scan this on a device with your passkey:
  https://auth.ck1.me/a/eyJhbGciOiJIUzI1NiJ9.eyJyZXMiOnsidHlwZSI6Im9iamVjdCIsImlkIjoic2l0ZW1hcC54bWwifSwid29yZCI6InNsdXJwIiwianRpIjoiZDMyNzQxYmY1ZTY1NDc2YzhlZTJkOWViNmJkMjU3YzUiLCJpc3MiOiJzZXJ2ZXMuY2sxLm1lIiwiYXVkIjoiYXV0aC5jazEubWUiLCJpYXQiOjE3ODI4MTY0MTAsImV4cCI6MTc4MjgxNjcxMH0.PXFdSRxIfAdHmiHNPhRQ3nGcb_q6WqfMezytG3xuWvE

(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.eyJyZXMiOnsidHlwZSI6Im9iamVjdCIsImlkIjoic2l0ZW1hcC54bWwifSwid29yZCI6InNsdXJwIiwianRpIjoiZDMyNzQxYmY1ZTY1NDc2YzhlZTJkOWViNmJkMjU3YzUiLCJpc3MiOiJzZXJ2ZXMuY2sxLm1lIiwiYXVkIjoiYXV0aC5jazEubWUiLCJpYXQiOjE3ODI4MTY0MTAsImV4cCI6MTc4MjgxNjcxMH0.PXFdSRxIfAdHmiHNPhRQ3nGcb_q6WqfMezytG3xuWvE' -o 'sitemap.xml'