firewalld (AlmaLinux/Rocky/CentOS)

sudo firewall-cmd --permanent --add-service=ssh
sudo firewall-cmd --permanent --add-service=http
sudo firewall-cmd --permanent --add-service=https
sudo firewall-cmd --reload

ufw (Ubuntu/Debian)

sudo ufw default deny incoming
sudo ufw default allow outgoing
sudo ufw allow OpenSSH
sudo ufw allow http
sudo ufw allow https
sudo ufw enable