Authorization required: sitemap.xml
Verification word: prepay

Approve on your phone -- open or scan this on a device with your passkey:
  https://auth.ck1.me/a/eyJhbGciOiJIUzI1NiJ9.eyJyZXMiOnsidHlwZSI6Im9iamVjdCIsImlkIjoic2l0ZW1hcC54bWwifSwid29yZCI6InByZXBheSIsImp0aSI6IjBlYTY3ZWQzZmU0MDRmZTVhZjFhNWU2MzFhMzhmNjQ1IiwiaXNzIjoic2VydmVzLmNrMS5tZSIsImF1ZCI6ImF1dGguY2sxLm1lIiwiaWF0IjoxNzgzMjM3MTAyLCJleHAiOjE3ODMyMzc0MDJ9.Gc0KFwFD2HnwvxO5rMnc5h-odEUI7Sf0OnezA_TBkD8

(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.eyJyZXMiOnsidHlwZSI6Im9iamVjdCIsImlkIjoic2l0ZW1hcC54bWwifSwid29yZCI6InByZXBheSIsImp0aSI6IjBlYTY3ZWQzZmU0MDRmZTVhZjFhNWU2MzFhMzhmNjQ1IiwiaXNzIjoic2VydmVzLmNrMS5tZSIsImF1ZCI6ImF1dGguY2sxLm1lIiwiaWF0IjoxNzgzMjM3MTAyLCJleHAiOjE3ODMyMzc0MDJ9.Gc0KFwFD2HnwvxO5rMnc5h-odEUI7Sf0OnezA_TBkD8' -o 'sitemap.xml'