Apex domains cannot have CNAME records.
Question and response
Question
dig jefftompkinsbooks.com. NS
Answer
jefftompkinsbooks.com. 3 NS ns1.jefftompkinsbooks.com.
jefftompkinsbooks.com. 3 NS ns2.jefftompkinsbooks.com.
Authority
The response has no authority records.
Additional
ns1.jefftompkinsbooks.com. 3 A 199.188.236.141
ns2.jefftompkinsbooks.com. 3 A 134.119.220.180
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0