Do the below steps to install PHP version 7.3 on centOS / Redhat 7 server. Run the command ‘cat /etc/redhat-release’ to check your OS version.
 
1. First you must install EPEL and remi repository on your Linux server

Command to install EPEL yum repository :

# yum install epel-release

You can install epel-release using yum command or you can download epel-release rpm

2. Run the below command to install remi repository

Command to install remi repository :

yum install http://rpms.remirepo.net/enterprise/remi-release-7.rpm

3. Now you can install php 7.3 using yum command.

Command to install php 7.3 :

# yum --enablerepo=remi-php73 install php

--enablerepo will use the repo /etc/yum.repos.d/remi-php73.repo

4. Yum will ask for confirmation before installing the package, enter ‘y’ to proceed with PHP 7.3 installation.

5. After installation type the command ‘php -v’ to verify the version of PHP installed.

—–
# php -v
PHP 7.3.4 (cli) (built: Apr 2 2019 13:48:50) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.3.4, Copyright (c) 1998-2018 Zend Technologies
—-