IP = 54.238.253.187
Content type of robots.txt is text/html!
Look up this url in the url tool
https://www.acmicpc.net/.well-known/acme-challenge: 403 text/html
https://www.acmicpc.net/.well-known/csvm: 403 text/html
https://www.acmicpc.net/.well-known/nostr.json: 403 text/html
https://www.acmicpc.net/.well-known/security.txt: 403 text/html
https://www.acmicpc.net/.well-known/traffic-advice: 403 text/html