How to Remove Server Signature

For Nginx

sudo nano /etc/nginx/nginx.conf

In http block:

server_tokens off;
more_set_headers "Server: Hidden";

(Install nginx-extras for more_set_headers)

For Apache

sudo nano /etc/apache2/conf-available/security.conf

Set:

ServerTokens Prod
ServerSignature Off

For PHP

sudo nano /etc/php/8.1/fpm/php.ini

expose_php = Off

Verify

curl -I https://yourdomain.com | grep Server