This step should have been completed upon the installation of RHEL 8.4, but if you haven’t, you can complete it with:

Update

# yum update

Now you are ready to install PHP 7.4 :

Check Available PHP Versions

# dnf module list php

Enable PHP 7.4 Module

# dnf module switch-to php:7.4

Install PHP and Dependancy Modules

# yum install php php-cli php-common

This step should have been completed upon the installation of Drupal 8 for getting PHPMailer function

Install Composer

# curl -sS https://getcomposer.org/installer | php

Move Composer binary to usr bin path

# mv composer.phar /usr/bin/composer

Check Composer Version

# composer --version

Go to Drupal root Directory and execute

To change the port for the SSH server, follow these steps:

• Log in to the server as root 
• Open the /etc/ssh/sshd_config file in your preferred text editor 
• Locate the following line: Port 22 and changed to New Port 2233
• Restart SSHD Service.

Use the following command for enabling additional SSH Port

sed -i 's/#Port 22/Port 22\nPort 2233/g' /etc/ssh/sshd_config

Firewall Configuration

This step should have been completed upon the installation of MySQL 5.7, but if you haven’t, you can complete it with:

System Updates

yum update

Install Repository

yum -y install yum localinstall https://dev.mysql.com/get/mysql57-community-release-el7-9.noarch.rpm

Now you are ready to install MySQL 5.7 with:

yum -y install mysql-community-server

Firewall Configuration

This step should have been completed upon the installation of PostgreSQL, but if you haven’t, you can complete it with:

Install Repository

yum -y install https://download.postgresql.org/pub/repos/yum/12/redhat/rhel-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm

Now you are ready to install pgAdmin with:

Install Dependencies