In order to choose the PHP mode you need to open the “Control Panel” of the hosting.
After you have entered the “Control Panel”, select the “WWW Domains” subsection of the “WWW” section.
Then select the domain you need (this is done by double clicking the left mouse button).
You get to the Domain editing page, here you need to find the “PHP mode” list, and it is located in the “Additional features” section.
After configuring, click “OK”.