Apex domains cannot have CNAME records.
Question and response
Question
dig vps.iamemonline.com. NS
Answer
vps.iamemonline.com. 4 NS dns32.cloudns.net.
vps.iamemonline.com. 4 NS dns34.cloudns.net.
vps.iamemonline.com. 4 NS dns31.cloudns.net.
vps.iamemonline.com. 4 NS dns33.cloudns.net.
Authority
The response has no authority records.
Additional
dns31.cloudns.net. 1 A 185.136.96.100
dns32.cloudns.net. 1 A 185.136.97.100
dns33.cloudns.net. 1 A 185.136.98.100
dns34.cloudns.net. 1 A 185.136.99.100
dns31.cloudns.net. 1 AAAA 2a06:fb00:1:0:0:0:1:100
dns32.cloudns.net. 1 AAAA 2a06:fb00:1:0:0:0:2:100
dns33.cloudns.net. 1 AAAA 2a06:fb00:1:0:0:0:3:100
dns34.cloudns.net. 1 AAAA 2a06:fb00:1:0:0:0:4:100
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0