How to set up Laravel Forge / nginx default site - nginx

Question

I have a nginx server with a single web site, managed by Laravel Forge. At the moment it responds to requests for a single subdomain: subdomain_a.mydomain.com.au. I need it to respond to requests for subdomain_b.mydomain.com.au, and also the raw IP address. How do I do that?
Here's the nginx config:
# FORGE CONFIG (DO NOT REMOVE!)
include forge-conf/subdomain_a.mydomain.com.au/before/*;
server {
listen 80;
listen [::]:80;
server_name subdomain_a.mydomain.com.au;
root /home/forge/subdomain_a.mydomain.com.au/public;
# FORGE SSL (DO NOT REMOVE!)
# ssl_certificate;
# ssl_certificate_key;
ssl_protocols TLSv1.2;
ssl_ciphers ECDHE-RSA-AES256-(truncated by me!!!);
ssl_prefer_server_ciphers on;
ssl_dhparam /etc/nginx/dhparams.pem;
add_header X-Frame-Options "SAMEORIGIN";
add_header X-XSS-Protection "1; mode=block";
add_header X-Content-Type-Options "nosniff";
index index.html index.htm index.php;
charset utf-8;
# FORGE CONFIG (DO NOT REMOVE!)
include forge-conf/subdomain_a.mydomain.com.au/server/*;
location / {
try_files $uri $uri/ /index.php?$query_string;
}
location = /favicon.ico { access_log off; log_not_found off; }
location = /robots.txt { access_log off; log_not_found off; }
access_log off;
error_log /var/log/nginx/subdomain_a.mydomain.com.au-error.log error;
error_page 404 /index.php;
location ~ \.php$ {
fastcgi_split_path_info ^(.+\.php)(/.+)$;
fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
fastcgi_index index.php;
include fastcgi_params;
}
location ~ /\.(?!well-known).* {
deny all;
}
}
# FORGE CONFIG (DO NOT REMOVE!)
include forge-conf/subdomain_a.mydomain.com.au/after/*;
I am new to both nginx and Forge, and this is due to be in production within a few days.

Answer 1

In forge open your website page, at the right bottom there is a dropup menu called "Files", click on "Edit Nginx configuration".
Now you have to change this directive (as described here) from:
add_header X-Frame-Options "SAMEORIGIN";
to
add_header X-Frame-Options "allow from https://your-ip-or-domain.tld"