Joseph Sible-Reinstate Monica's questions

I have Web servers that run multiple virtual hosts, and I'd like to keep eavesdroppers from telling which virtual host a client is accessing. There's already a TLS extension for solving this problem: encrypted SNI. I see that Cloudflare supports it on its servers, and that Firefox has a setting to enable it on the client. I can't find any documentation of how to enable this on servers of my own, though. How do I do this? (I'm not tied to any particular server stack and will accept any working setup/architecture other than "put it behind Cloudflare".)