Authorization required: sitemap.xml
Verification word: undertook

Approve on your phone -- open or scan this on a device with your passkey:
  https://auth.ck1.me/a/eyJhbGciOiJIUzI1NiJ9.eyJyZXMiOnsidHlwZSI6Im9iamVjdCIsImlkIjoic2l0ZW1hcC54bWwifSwid29yZCI6InVuZGVydG9vayIsImp0aSI6IjUzMmUwOTk4MjcxZDQxM2ZhODRiNjE4MDQwMzc0OTg0IiwiaXNzIjoic2VydmVzLmNrMS5tZSIsImF1ZCI6ImF1dGguY2sxLm1lIiwiaWF0IjoxNzg1NDQ0MTMyLCJleHAiOjE3ODU0NDQ0MzJ9.51zqeJU6G2Z0-qWqp6XwPUyH8EC7RpC9EFkC_A3LcvY

(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.eyJyZXMiOnsidHlwZSI6Im9iamVjdCIsImlkIjoic2l0ZW1hcC54bWwifSwid29yZCI6InVuZGVydG9vayIsImp0aSI6IjUzMmUwOTk4MjcxZDQxM2ZhODRiNjE4MDQwMzc0OTg0IiwiaXNzIjoic2VydmVzLmNrMS5tZSIsImF1ZCI6ImF1dGguY2sxLm1lIiwiaWF0IjoxNzg1NDQ0MTMyLCJleHAiOjE3ODU0NDQ0MzJ9.51zqeJU6G2Z0-qWqp6XwPUyH8EC7RpC9EFkC_A3LcvY' -o 'sitemap.xml'