PHP 7.0 reached end of life on 03 Dec 2018 and is no longer being updated. It's strongly recommended to upgrade to the latest version as soon as possible. You can read the official PHP migration guide here.
Installing PHP 7.0 on Server 2019
Prerequisites
Windows Server 2019 installed and updated
Administrative access to the server
Internet connection for downloading PHP
IIS (Internet Information Services) role installed
Installation
Download PHP 7.0 from the official PHP website
Extract the downloaded ZIP file to C:\PHP7
Rename php.ini-production to php.ini
Open IIS Manager
Install CGI feature if not already installed
Add handler mapping for PHP in IIS
Configure FastCGI settings for PHP
Add C:\PHP7 to system PATH
Restart IIS
Verification
Create a new file named phpinfo.php in your web root directory
Add the following code to phpinfo.php:
<?php phpinfo(); ?>
Open a web browser and navigate to http://localhost/phpinfo.php