Apex domains cannot have CNAME records.
Google
Domain verification
google-site-verification=uiQdALO-_VPT9Pa4rEk_S5XKqE-nDiE_2sJbqhDApJo
Microsoft
Domain verification
MS=ms68684398
Pardot
Domain verification
pardot813153=35383a355bc9e37f2c98a432e9c73e1672a906f2fec75d02ce1b07f8a25496e4
Sophos
Domain verification
sophos-domain-verification=8fd6ecda824ed3ba356d1fbed5ace0f8ac4add4f5a0f63817d3f0884c77a645b
Trend Micro Email Security
Domain verification
tmes=2729ff242fde5ccc58052987e1bef867
Zone apex
Start of authority
Email
Serial
2025120101
Refresh
8h
Retry
1h
Expire
7d
Negative cache TTL
1d