NGINX IP to Domain Redirect

Server Setup:

1. VPS
2. Plesk 12.5
3. Centos 7
4. NGINX as reverse proxy to Apache 2.4
5. Path to NGINX config: /etc/nginx/nginx.conf

Plesk provides a GUI Apache & nginx Settings dialog box, but is unable to accept server{} blocks from there.

I've tried the following within /etc/nginx/nginx.conf, and several variations thereof, without success:

server {
server_name xx.xx.xx.xx;
return 301 https://domain.com$request_uri
}

I've also tried the following within...

NGINX IP to Domain Redirect