Apex domains cannot have CNAME records.
Question and response
Question
dig vercel-dns-013.com. NS
Answer
vercel-dns-013.com. 5 NS ns1.vercel-dns-013.com.
vercel-dns-013.com. 5 NS ns3.vercel-dns-013.com.
vercel-dns-013.com. 5 NS ns2.vercel-dns-013.com.
vercel-dns-013.com. 5 NS ns4.vercel-dns-013.com.
Authority
The response has no authority records.
Additional
ns1.vercel-dns-013.com. 5 A 205.251.194.9
ns2.vercel-dns-013.com. 5 A 205.251.193.113
ns3.vercel-dns-013.com. 5 A 205.251.198.42
ns4.vercel-dns-013.com. 5 A 205.251.196.219
ns1.vercel-dns-013.com. 5 AAAA 2600:9000:5302:900:0:0:0:1
ns2.vercel-dns-013.com. 5 AAAA 2600:9000:5301:7100:0:0:0:1
ns3.vercel-dns-013.com. 5 AAAA 2600:9000:5306:2a00:0:0:0:1
ns4.vercel-dns-013.com. 5 AAAA 2600:9000:5304:db00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0