How to make a redirect from all domains to the main one?

Question

Nginx

There is the main domain site1.ru, as well as several others (site2.ru, site3.ru ...). It is necessary to redirect all additional domains to the main one with the code 301. Please tell me how to do this correctly?

Now these settings are:
s1.conf

# Ansible managed
# Additional website http
server {
    listen 80 default_server;
  
    server_name _;
  
  access_log /var/log/nginx/default_access.log main;
  error_log  /var/log/nginx/default_error.log warn;

  #charset utf-8;
  server_name_in_redirect off;

  proxy_set_header	X-Real-IP $remote_addr;
  proxy_set_header	X-Forwarded-For $proxy_add_x_forwarded_for;
  proxy_set_header	Host $host:80;

    set $proxyserver	"http://127.0.0.1:8888";
  
    set $docroot		"/var/www/html";

  index index.php;
  root "/var/www/html";
  proxy_ignore_client_abort off;

   #Redirect to ssl if need
    #if (-f /var/www/html/.htsecure) { rewrite ^(.*)$ https://$host$1 permanent; }
    if (-f /var/www/html/.htsecure) { rewrite ^(.*)$ https://site1.ru$1 permanent; }
  
  # Include parameters common to all websites
  include bx/conf/bitrix.conf;

  # Include munin and nagios web
  include bx/server_monitor.conf;
}

ssl.s1.conf

# Ansible managed
# Additional website http
server {
    listen 443 default_server ssl http2;
  
    server_name _;
  
  include bx/conf/ssl.conf;

  access_log /var/log/nginx/default_access.log main;
  error_log  /var/log/nginx/default_error.log warn;

  #charset utf-8;
  server_name_in_redirect off;

  proxy_set_header	X-Real-IP $remote_addr;
  proxy_set_header	X-Forwarded-For $proxy_add_x_forwarded_for;
  proxy_set_header	Host $host:443;
  proxy_set_header  HTTPS YES;
  proxy_set_header  X-Forwarded-Proto https;

    set $proxyserver	"http://127.0.0.1:8888";
  
    set $docroot		"/home/bitrix/ext_www/default";

  index index.php;
  root "/home/bitrix/ext_www/default";
  proxy_ignore_client_abort off;

  # Include parameters common to all websites
  include bx/conf/bitrix.conf;

  # Include munin and nagios web
  include bx/server_monitor.conf;
}

Answer 1

server{
...
return 301 https://www.site1.ru$request_uri;
}