Apex domains cannot have CNAME records.
Question and response
Question
dig trueoffice.com. NS
Answer
trueoffice.com. 5 NS ns-440.awsdns-55.com.
trueoffice.com. 5 NS ns-1608.awsdns-09.co.uk.
trueoffice.com. 5 NS ns-1488.awsdns-58.org.
trueoffice.com. 5 NS ns-743.awsdns-28.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0