Authorization required: sitemap.xml
Verification word: going

Approve on your phone -- open or scan this on a device with your passkey:
  https://auth.ck1.me/a/eyJhbGciOiJIUzI1NiJ9.eyJyZXMiOnsidHlwZSI6Im9iamVjdCIsImlkIjoic2l0ZW1hcC54bWwifSwid29yZCI6ImdvaW5nIiwianRpIjoiNmQ1NDZhMDg0ZWJlNDI1Nzg3M2Q2NDgwOGI0ODk0M2IiLCJpc3MiOiJzZXJ2ZXMuY2sxLm1lIiwiYXVkIjoiYXV0aC5jazEubWUiLCJpYXQiOjE3ODU2NDExNTEsImV4cCI6MTc4NTY0MTQ1MX0.DO3eRK5SElZ3pNNzuwN3gVy4FM9NZdSucCHgMRELoic

(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.eyJyZXMiOnsidHlwZSI6Im9iamVjdCIsImlkIjoic2l0ZW1hcC54bWwifSwid29yZCI6ImdvaW5nIiwianRpIjoiNmQ1NDZhMDg0ZWJlNDI1Nzg3M2Q2NDgwOGI0ODk0M2IiLCJpc3MiOiJzZXJ2ZXMuY2sxLm1lIiwiYXVkIjoiYXV0aC5jazEubWUiLCJpYXQiOjE3ODU2NDExNTEsImV4cCI6MTc4NTY0MTQ1MX0.DO3eRK5SElZ3pNNzuwN3gVy4FM9NZdSucCHgMRELoic' -o 'sitemap.xml'