sudo nginx -s reload

nginx.conf

server {
	listen 80 default_server;
	listen [::]:80 default_server;

	root /home/sample/Laravel_app;
	index index.php index.html index.htm index.nginx-debian.html;

	charset utf-8;
	gzip on;
	server_name _;

	location / {
		try_files $uri $uri/ /index.php?$query_string;
	}

        location ~ \.php$ {
             fastcgi_split_path_info ^(.+\.php)(/.+)$;
		fastcgi_pass unix:/var/run/php/php8.0-fpm.sock;
       	fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
      	include fastcgi_params;
        }

	# deny access to .htaccess files, if Apache's document root
	# concurs with nginx's one
	location ~ /\.ht {
		deny all;
	}
       
       location /subfoldername{
		alias /home/sample/Laravel_app/subfoldername/public;
		index index.php index.htm index.html;
		try_files $uri $uri/ @subfoldername;
		
		#add_header my_string 'start'; # <- これを追加
		#add_header request_filename $request_filename; # <- これを追加
		#add_header my_document_root $document_root; # <- これを追加
		#add_header fastcgi_script_name $fastcgi_script_name; # <- これを追加
		#add_header my_fastcgi_path_info $fastcgi_path_info; # <- これを追加
		#add_header my_string_2 ‘end’; # <- これを追加

        	location ~ [^/]\.php(/|$) {
			include fastcgi_params;
			fastcgi_split_path_info ^(.+\.php)(/.+)$;
			fastcgi_pass unix:/var/run/php/php8.0-fpm.sock;
			fastcgi_index index.php;
			fastcgi_param SCRIPT_FILENAME $request_filename;
			#fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
			fastcgi_param PATHINFO $fastcgi_path_info;
			fastcgi_param PATH_TRANSLATED $document_root$fastcgi_path_info;
        	}
    	}
	location @subfoldername{
		rewrite /subfoldername/(.*)$ /subfoldername/index.php?/$1 last;
	}

}