Apex domains cannot have CNAME records.
Question and response
Question
dig prolocation.nl. NS
Answer
prolocation.nl. 4 NS cloudns3.prolocation.net.
prolocation.nl. 4 NS ns3.as41887.io.
prolocation.nl. 4 NS cloudns7.prolocation.net.
prolocation.nl. 4 NS cloudns8.prolocation.net.
prolocation.nl. 4 NS ns1.as41887.nl.
prolocation.nl. 4 NS cloudns4.prolocation.net.
Authority
The response has no authority records.
Additional
ns1.as41887.nl. 4 A 94.228.129.129
ns3.as41887.io. 4 A 165.227.154.158
cloudns3.prolocation.net. 4 A 185.136.96.88
cloudns4.prolocation.net. 4 A 185.136.97.88
cloudns7.prolocation.net. 4 A 185.136.98.88
cloudns8.prolocation.net. 4 A 185.136.99.88
ns1.as41887.nl. 4 AAAA 2a00:d00:ff:129:94:228:129:129
ns3.as41887.io. 4 AAAA 2a03:b0c0:3:d0:0:0:50d:6001
cloudns3.prolocation.net. 4 AAAA 2a06:fb00:1:0:0:0:1:88
cloudns4.prolocation.net. 4 AAAA 2a06:fb00:1:0:0:0:2:88
cloudns7.prolocation.net. 4 AAAA 2a06:fb00:1:0:0:0:3:88
cloudns8.prolocation.net. 4 AAAA 2a06:fb00:1:0:0:0:4:88
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0