How to Correct 'nginx: [emerg] "stream" directive is not allowed here' - ssl

Question

The Question
Why does the following Nginx configuration return nginx: [emerg] "stream" directive is not allowed here in /etc/nginx/sites-enabled/default:1?
Nginx Configuration...
stream {
map $ssl_preread_server_name $upstream {
example.com 1051;
}
upstream 1051 {
server 127.0.0.1:1051;
}
server {
listen 443;
proxy_pass $upstream;
ssl_preread on;
}
}
Version / Build information...
OS: Debian 10
Here is the stripped down nginx -V output confirming the presence of the modules I understand I need...
nginx version: nginx/1.14.2
TLS SNI support enabled
configure arguments: ... --with-stream=dynamic --with-stream_ssl_module --with-stream_ssl_preread_module ...
The Context
I have a single static IP address. At the static IP address, I am setting up a reverse proxy Nginx server to forward traffic to a variety of backend services. Several of the services are websites with unique domain names.
+-----+ +----------------------+ +---------+
| WAN | <----> | Nginx Reverse Proxy | <----> | Service |
+-----+ +----------------------+ +---------+
At boot, the service uses systemd to run this port forwarding ssh command to connect to the reverse proxy: ssh -N -R 1051:localhost:443 tunnel#example.com (That is working well.)
I want the certificate to reside on the service - not the reverse proxy. From what I understand I need to leverage SNI on Nginx to passthrough the SSL connections bases on domain name. But I cannot get the Nginx reverse proxy to passthrough SSL.
Resources
Here are a few of the resources I have pored over...
https://serverfault.com/questions/625362/can-a-reverse-proxy-use-sni-with-ssl-pass-through
https://nginx.org/en/docs/stream/ngx_stream_core_module.html
https://nginx.org/en/docs/stream/ngx_stream_ssl_preread_module.html
https://www.amitnepal.com/nginx-ssl-passthrough-reverse-proxy
https://serverfault.com/questions/1049158/nginx-how-to-combine-ssl-preread-protocol-with-ssl-preread-server-name-ssh-mul

Answer 1

The problem was I tried to embed a stream block inside an http block. I was not properly accounting for the include in /etc/nginx/nignx.conf file.