Apex domains cannot have CNAME records.
Question and response
Question
dig webropol.com. NS
Answer
webropol.com. 5 NS cns1.cloudpit.de.
webropol.com. 5 NS cns3.cloudpit.io.
webropol.com. 5 NS cns2.cloudpit.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0