title: what is sni_endpoint and how to add it in heroku
body: <p>I am trying to add a custom domain to my Heroku app but after adding the custom domain the given Dns target is now working. Whenever I try to visit my Dns target link, It says that <strong>synthetic-stonecrop-p4oa311n91p2gcgbqide0d1b.herokudns.com didn’t send any data.</strong> I guess the procedure of adding a new domain is updated but heroku did not mentioned it in there official docs. I want to know what this <code>sni_endpoint</code> is and how to configure it for my app. Any help will be appriciated. Thanks !</p>
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