dcv.cloudflare.com has no TXT records.
Question and response
Question
dig dcv.cloudflare.com. TXT
Answer
The response has no answer records.
Authority
dcv.cloudflare.com. 1800 SOA graham.ns.cloudflare.com. dns.cloudflare.com. 2397395187 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0