Set up multiple websites or stores with nginx

nginx-magento2-multiwebsite.conf

map $http_host $MAGE_RUN_CODE {
    hostnames; # indicates that values can be hostnames with prefix or suffix mask.

    default	base;
    *.ch   	ch;
    *.de	  de;
    *.at	  at;
}

server {
  listen 443 ssl http2;
  server_name <domains-list>;

  set $MAGE_ROOT <magento_path>/pub;
  set $MAGE_MODE production;
  set $MAGE_RUN_TYPE website;
  
  # Logs, FPM and other configs
  
  include /var/www/html/magento2/nginx.conf;
}