File contents depending on the device?

Question

PHP

In general, there are two files index.html and index2.html. It is
necessary that when opening the index.php file from desktops, the contents of index.html are loaded into it, and when opened from mobiles, index2.html is loaded.
This is done so that it does not depend on which devices open the site, the path was the same, but the versions of the site are different.

Answer 1

There is already a good solution:
mobiledetect.net
It will be something like this:

if ( $detect->isMobile() ) {
        include('youfile.html');
}