We recently had an issue regarding a function in an Azure Function App Service that was still running after being disabled using the Azure Portal (and hence the function.json)
We used an Azure Function App Service running on an App Service Plan. The timer triggered function was precompiled using C# (so a .dll) developed in Visual Studio 2017.
I recently got a request to install a PHP extension in an Azure Web Service running PHP 7.1, Cake PHP and MySQL. The extension to install was Imagick 3.4.3 x64, which is used for all kinds of image manipulation. The marketplace extension Composer was installed already.
Since Azure Web Service is a managed service, installing non-marketplace extensions is not as straight forward as on a managed machine running Windows or Linux. But even though the required steps are not officially documented, there are some resources available on the issue. I used the following manual.