nslookup acme-v02.api.letsencrypt.org
Server:         2a02:4780:8:abcd::153
Address:        2a02:4780:8:abcd::153#53

Non-authoritative answer:
acme-v02.api.letsencrypt.org    canonical name = prod.api.letsencrypt.org.
prod.api.letsencrypt.org        canonical name = ca80a1adb12a4fbdac5ffcbc944e9a61.pacloudflare.com.
Name:   ca80a1adb12a4fbdac5ffcbc944e9a61.pacloudflare.com
Address: 172.65.32.248
Name:   ca80a1adb12a4fbdac5ffcbc944e9a61.pacloudflare.com
Address: 2606:4700:60:0:f53d:5624:85c7:3a2c