How to make custom domain from docker available on mobile device in the same network

mobile.hosts.example

# /etc/hosts
127.0.0.1 startupkin.test

# /etc/nginx/sites-available/startupkin.test.conf
server {
    listen 80;
    listen [::]:80;

    server_name startupkin.test;
    root /var/www/startupkin/public;
    index index.php;
    
    location / {
        try_files $uri $uri/ /index.php$is_args$args;
    }
    
    location ~ \.php$ {
        try_files $uri /index.php =404;
        fastcgi_pass php-upstream;
        fastcgi_index index.php;
        fastcgi_buffers 16 16k;
        fastcgi_buffer_size 32k;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_read_timeout 600;
        include fastcgi_params;
    }

    location ~ /\.ht {
        deny all;
    }

    error_log /var/log/nginx/startupkin.test_error.log;
    access_log /var/log/nginx/startupkin.test_access.log;
}

# Android app for manage hosts at mobile
https://play.google.com/store/apps/details?id=dns.hosts.server.change&hl=en_US

# Settings at the app
# Add doamin with: 
IP = 192.168.1.4 (IP address of computer)
Domain: startupkin.test (your custom doamin)