IP = 52.4.1.216
Content type of robots.txt is application/xml!
Look up this url in the url tool
https://class.coursera.org/.well-known/acme-challenge: 403 application/xml
https://class.coursera.org/.well-known/csvm: 403 application/xml
https://class.coursera.org/.well-known/nostr.json: 403 application/xml
https://class.coursera.org/.well-known/security.txt: 403 application/xml
https://class.coursera.org/.well-known/traffic-advice: 403 application/xml