For more details on what becomes public when a Certificate Authority (such as Let's Encrypt) signs a certificate search for Certificate Transparency. Thus if you use an reputable Certificate Authority your domain information is publicly available to everyone, not sharing it on this forum won't hide your domain just make it harder for us to assist you.
Here a few of the many search results for Certificate Transparency.
And from Issuance Policy section of this forum Transparent certificate policy
And Certificate Transparency - Wikipedia
Certificate Transparency Required on Google Chrome - #5 by mcpherrinm and a quota from it