_acme-challenge.heysender.com has no NS records.
NS records for this zone are defined at heysender.com.
NS records for this zone are defined at heysender.com.
Question and response
Question
dig heysender.com.80ad5b49141b73d0.dcv.cloudflare.com. NS
Answer
The response has no answer records.
Authority
dcv.cloudflare.com. 1800 SOA graham.ns.cloudflare.com. dns.cloudflare.com. 2398329647 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0