How to change PHP version using .htaccess file ?

What is the best way to change PHP version of a web application that runs on the same server with multiple sites that need a different PHP version?

Add the following lines inside the website’s .htaccess file. (.htaccess file under the same folder/directory of the files hosted for the web application or website):

To switch to PHP 4.4:
AddHandler application/x-httpd-php4 .php

To switch to PHP 5.0:
AddHandler application/x-httpd-php5 .php

To switch to PHP 5.1:
AddHandler application/x-httpd-php51 .php

To switch to PHP 5.2:
AddHandler application/x-httpd-php52 .php

To switch to PHP 5.3:
AddHandler application/x-httpd-php53 .php

To switch to PHP 5.4:
AddHandler application/x-httpd-php54 .php

To switch to PHP 5.5:
AddHandler application/x-httpd-php55 .php

To switch to PHP 5.6:
AddHandler application/x-httpd-php56 .php

To switch to PHP 7:
AddHandler application/x-httpd-php7 .php

To switch to PHP 7.1:
AddHandler application/x-httpd-php71 .php

To switch to PHP 8:
AddHandler application/x-httpd-php8 .php

To switch to PHP 8.1:
AddHandler application/x-httpd-php81 .php