NGINX HTTPS not redirecting properly

I followed Cerbot's instructions to get a HTTPS certificate for NGINX in my Debian server for a domain, but the HTTPS is not redirecting properly.

I got the following in etc/nginx/conf.d/app.conf:

server {
    server_name mnpd.khkm.dev www.mnpd.khkm.dev;
    # listen 8080;
    server_tokens off;
    location /.well-known/acme-challenge/ {
        root /var/www/certbot;
    }
    location / {
        # return 301 https://mnpd.khkm.dev$request_uri;
        proxy_pass http://mnpd.khkm.dev;
    }

    listen [::]:443 ssl ipv6only=on; # managed by Certbot
    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/mnpd.khkm.dev/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/mnpd.khkm.dev/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

}
server {
    if ($host = mnpd.khkm.dev) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


    listen 80;
    listen [::]:80;
    server_name mnpd.khkm.dev www.mnpd.khkm.dev;
    return 404; # managed by Certbot
}

In Chrome, when I go to https://mnpd.khkm.dev/, I get:

mnpd.khkm.dev redirected you too many times.
Try deleting your cookies.
ERR_TOO_MANY_REDIRECTS

I found this Stack Overflow answer where I looked at the "Network" tab in the web console and saw that the page is constantly being redirected to https://mnpd.khkm.dev/. The NGINX configuration should be listening to port 443 for the HTTPS, so why isn't it loading and constantly being redirected? (I expect the default NGINX page to be loaded.)

I had to remove:

location / {
    # return 301 https://mnpd.khkm.dev$request_uri;
    proxy_pass http://mnpd.khkm.dev;
}

from my etc/nginx/conf.d/app.conf file.

This was answered by a user in the Unix & Linux forums which also has more details.