How to solve non-www redirection to www Nginx?

Unfortunately Certbot creates the nginx redirects using if with the $host variable which is problematic.

It is best to have the redirect in a separate server section as follows.

# Redirect all requests to betafox.net URLs to corresponding www.betafox.net URLs
server {
    listen 80;
    listen 443 ssl http2;

    ssl_certificate /etc/letsencrypt/live/betafox.net-0001/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/betafox.net-0001/privkey.pem; # managed by Certbot

    server_name betafox.net;

    return 301 https://www.betafox.net$request_uri;
}

# Redirect all other subdomain HTTP requests to HTTPS.
server {
    listen 80;

    server_name *.betafox.net;

    return 301 https://$http_host$request_uri;:
}

# Removed the server block for port 80, it looked meaningless

server {
    # Removed the default_server, default_server should not be the actual website
    listen 443 ssl;
    listen [::]:443 ssl;

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

    server_name betafox.net *.betafox.net;
    # Maximum file upload size is 4MB - change accordingly if needed
    client_max_body_size 512M;
    client_body_buffer_size 128k;
    include snippets/letsencrypt-nginx-certs.conf;
    include snippets/letsencrypt-nginx-route.conf;

    location / {
        try_files $uri $uri/ /index.php?q=$uri&$args;
    }
    error_page 404 /404.html;

    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root /usr/share/nginx/html;
    }

    location ~ \.php$ {
        include snippets/fastcgi-php.conf;
        fastcgi_pass unix:/etc/alternatives/php-fpm.sock;
    }
    ssl_certificate /etc/letsencrypt/live/betafox.net-0001/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/betafox.net-0001/privkey.pem; # managed by Certbot
}