ip166.217-145-73.hosted-by.nitro-cloud.com has no CNAME records.
Question and response
Question
dig ip166.217-145-73.hosted-by.nitro-cloud.com. NS
Answer
The response has no answer records.
Authority
hosted-by.nitro-cloud.com. 49 SOA ns1.cprapid.com. root.178-162-242-207.cprapid.com. 2026012901 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0