IP = 172.66.154.160
Content type of robots.txt is text/html; charset=UTF-8!
Look up this url in the url tool
https://oj.leetcode.com/.well-known/acme-challenge: 530 text/html; charset=UTF-8
https://oj.leetcode.com/.well-known/csvm: 530 text/html; charset=UTF-8
https://oj.leetcode.com/.well-known/nostr.json: 530 text/html; charset=UTF-8
https://oj.leetcode.com/.well-known/security.txt: 530 text/html; charset=UTF-8
https://oj.leetcode.com/.well-known/traffic-advice: 530 text/html; charset=UTF-8