I am running Ampps 4.9.3 on Mac, and I am trying to install Laravel 5.6, which has a dependency on PHP 7.1.3. The latest version of Ampps says it supports 7.1.8, but I can't figure out how to change it from 7.1.2. Sorry if I'm missing something obvious, thanks for your help!
As @IgnazioC said, you can replace the contents of the relevant php version with a new one. You can grab the latest PHP 7.1 windows builds from https://windows.php.net/download#php-7.1
Make sure you download the VC14 x86 Thread Safe build, because this is what Ampps uses. You can also download newer versions of ionCube, XDebug and Opcache, but this isn't usually required.