Unixcop published a tutorial about installing PHP 7.X in CentOS 9 Stream.

How to Install PHP 7.X in CentOS 9 Stream

CentOS 9 Stream incorporates many applications and packages with recent versions. This is generally good because it allows us to take advantage of the new features they incorporate. However, there are times when we have to install previous versions of components such as PHP. 

How to Install PHP 7.X in CentOS 9 Stream - Unix / Linux the admins Tutorials