Help setting up a 2nd Nextcloud instance on same server - nginx

I have a working server with these specs:

Nextcloud 21.0.1
4CPU
8GB Ram
Ubuntu 20.04.2
PHP 8.0.7
PostgreSQL 13.3
Nginx server

Regular installation using this guide: https://github.com/ReinerNippes/nextcloud/tree/nextcloud-reloaded

I would like to install a 2nd instance of nextcloud on the same server.

I am following a few tutorials starting from the nginx configuration files located in /etc/nginx/conf.d
so i pointed a new domain to the server, and created a .conf file for it with the following:

  GNU nano 4.8                                                   exampledomain.conf                                                              

upstream php-handler {
server unix:/run/php/php8.0-fpm.sock;
}

server {
listen 80 default_server;
server_name cloud.exampledomain.com;
root /var/www/cloud.exampledomain;
location ^~ /.well-known/acme-challenge {
default_type text/plain;
root /var/www/letsencrypt;
}
location / {
return 301 https://$host$request_uri;
}
}

I put just a test index.html file in the new directory, first i am trying to reach the new domain before copying the nextcloud setup files and database, etc

Whats happening is, when i test the new domain, i get an error message: " Access through untrusted domain" from nextcloud.
How do i make it go to the new directory without interfering with the existing nextcloud setup?
Thank you