How to use proxy_pass in nginx?

I am trying to setup nginx to redirect (/home) to Home Assistant (home-assistant.io) on my raspberry pi, however when I try to browse to (www.mydomain.com/home) I get the following:

{"message": "404: Not Found", "result": "error"}

Here is my config file:

server {
    server_name mydomain.com www.mydomain.com;
    listen 80 default_server;
    listen [::]:80 default_server ipv6only=on;
    return 301 https://$host$request_uri;
}


server {
    root /var/www/html;
    server_name mydomain.com www.mydomain.com;
    listen 443 default_server;
    ssl on;

    #SSL
    add_header Strict-Transport-Security "max-age=31536000; includeSubdomains";
    ssl_certificate /etc/letsencrypt/live/http://ift.tt/1sCsmTd;
    ssl_certificate_key /etc/letsencrypt/live/http://ift.tt/1XWmnoF;
    ssl_dhparam /etc/ssl/certs/dhparam.pem;
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    ssl_ciphers "EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH:!aNULL:!eNULL:!EXPORT:!DES:!MD5:!PSK:!RC4";
    ssl_prefer_server_ciphers on;
    ssl_session_cache shared:SSL:10m;

    proxy_buffering off;

    location /home {
        proxy_pass http://localhost:8123;
    }


}

Have tried googling and searching stack overflow and tried numerous changes but can not get anything to work!

How can I achieve this? or what am I missing?