proxy.onice.io has no CNAME records.
Question and response
Question
dig proxy.onice.io. NS
Answer
The response has no answer records.
Authority
onice.io. 2636 SOA dnsmaster.ttc.cz.apptocloud.net. admin.apptocloud.net. 2026022507 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0