======== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.9.8
- Linux/BSD distribution name and version: Ubuntu 18.04
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

I cannot seem to get adminer to work.

Created a folder /opt/www/adminer:
drwxr-xr-x  2 root      root      4096 Jul 18 08:58 adminer/

Downloaded latest adminer and saved as index.php:
-rwxr-xr-x 1 root root 467815 Jun 28 21:58 index.php*

Modified the adminer tmplate:

location = /adminer {
    return 301 /adminer/;
}

location ~ ^/adminer {
    include /etc/nginx/templates/hsts.tmpl;
    include /etc/nginx/templates/fastcgi_php.tmpl;

    # fastcgi_index latest.php;
    fastcgi_param SCRIPT_FILENAME /opt/www/adminer/index.php;

    # Access control
    #allow 127.0.0.1;
    #allow 192.168.1.10;
    #allow 192.168.1.0/24;
    #deny all;
}

Added adminer template to /etc/nginx/sites-available/00-default-ssl.conf:

server {
    listen 443;
    server_name _;

    root /var/www/html;
    index index.php index.html;

    include /etc/nginx/templates/misc.tmpl;
    include /etc/nginx/templates/ssl.tmpl;
    include /etc/nginx/templates/iredadmin.tmpl;
    include /etc/nginx/templates/adminer.tmpl;
    include /etc/nginx/templates/roundcube.tmpl;
    include /etc/nginx/templates/sogo.tmpl;
    include /etc/nginx/templates/netdata.tmpl;
    include /etc/nginx/templates/php-catchall.tmpl;
}

I restarted nginx, got no errors but when I go to https://www.myiredmaildomain.com/adminer I get:

404 not found. Any suggestion what could be wrong?