Apex domains cannot have CNAME records.
Question and response
Question
dig robly.com. NS
Answer
robly.com. 3 NS ns-1597.awsdns-07.co.uk.
robly.com. 3 NS ns-156.awsdns-19.com.
robly.com. 3 NS ns-859.awsdns-43.net.
robly.com. 3 NS ns-1169.awsdns-18.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0