Why It's not working?

[jlguerrero]

Follow this guide

DNS & DKIM Questions : Pre-Install Prep

In HESTIA you have to: create NS records ** ns1.domain.tld ** ns2.domain.tld also create A records ** ns1.domain.tld A 123.123.123.123 (IP of your server) ** ns2.domain.tld A 123.123.123.123 (IP of your ns or a different dns server if configured) Then, go to the domain registrar and set: ns1.domain.tld and ns2.domain.tld as the DNS servers for every domain that you use. After that, the world will recognize and use your DNS servers as the true ones. You may check https://dnschecker.org…

You have not created the A records for ns1 and ns2