Apex domains cannot have CNAME records.
Question and response
Question
dig upmind.app. NS
Answer
upmind.app. 5 NS dave.ns.cloudflare.com.
upmind.app. 5 NS adi.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
adi.ns.cloudflare.com. 4 A 108.162.192.56
adi.ns.cloudflare.com. 4 A 172.64.32.56
adi.ns.cloudflare.com. 4 A 173.245.58.56
dave.ns.cloudflare.com. 4 A 108.162.193.109
dave.ns.cloudflare.com. 4 A 172.64.33.109
dave.ns.cloudflare.com. 4 A 173.245.59.109
adi.ns.cloudflare.com. 4 AAAA 2606:4700:50:0:0:0:adf5:3a38
adi.ns.cloudflare.com. 4 AAAA 2803:f800:50:0:0:0:6ca2:c038
adi.ns.cloudflare.com. 4 AAAA 2a06:98c1:50:0:0:0:ac40:2038
dave.ns.cloudflare.com. 4 AAAA 2606:4700:58:0:0:0:adf5:3b6d
dave.ns.cloudflare.com. 4 AAAA 2803:f800:50:0:0:0:6ca2:c16d
dave.ns.cloudflare.com. 4 AAAA 2a06:98c1:50:0:0:0:ac40:216d
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0