https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/deploying_different_types_of_servers/setting-apache-http-server_deploying-different-types-of-servers

Install ModSecurity on CentOS 7

1. Enter the following into a terminal window:
sudo yum install mod_security

If prompted, pres y and hit Enter to allow the process to complete.
2. Restart the Apache service:

sudo systemctl restart httpd.service
3. Check the software version (should be 2.8.0 or later):

yum info mod_security
Step: 3 Configure ModSecurity

Upon installation, ModSecurity is set to log events according to default rules. You’ll need to edit the configuration file to adjust the rules to detect and block traffic.

The default configuration file is /etc/modsecurity/modsecurity.conf-recommended.
1. Copy and rename the file:
sudo cp /etc/modsecurity/modsecurity.conf-recommended /etc/modsecurity/modsecurity.conf

2. Next, change the ModSecurity detection mode. First, move into the /etc/modsecurity folder:
sudo cd /etc/modsecurity

3. Open the configuration file in a text editor (we will be using nano):
sudo nano modsecurity.conf
___________________________________________________________________________________________________
Now after installation 

Add this line in httpd.conf (full path-> /etc/httpd/conf/httpd.conf)
SecRuleEngine on
SecServerSignature " "
ServerSignature On
ServerTokens Prod