Apex domains cannot have CNAME records.
Question and response
Question
dig digitalxraysystem.com. NS
Answer
digitalxraysystem.com. 2 NS ns2.digitalxraysystem.com.
digitalxraysystem.com. 2 NS ns1.digitalxraysystem.com.
Authority
The response has no authority records.
Additional
ns1.digitalxraysystem.com. 2 A 38.7.199.214
ns2.digitalxraysystem.com. 2 A 45.80.192.116
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0