Azure Website–Allowing different file types for download

An azure website out of the box will not allow you to download static content files such as JSON, MP4, etc. If you need to enable this feature, you need to add a web.config file in the site/wwwroot folder with the following contents

<?xml version="1.0"?>
<configuration>
     <system.webServer>
         <staticContent>
             <!--following needed only if extensions were defined at a different level -->
             <!-- <remove  fileExtension=".json" /> -->
             <!-- for a good list of other mimetypes see: https://www.sitepoint.com/mime-types-complete-list/ -->
             <mimeMap fileExtension="json" mimeType="application/json" />
             <mimeMap fileExtension="mp4" mimeType="video/mp4" />
             <mimeMap fileExtension="ogg" mimeType="audio/ogg" />
             <mimeMap fileExtension="m4a" mimeType="audio/mp4" />
             <mimeMap fileExtension="flv" mimeType="video/x-flv" />
             <mimeMap fileExtension="woff" mimeType="application/font-woff" />
             <mimeMap fileExtension="woff2" mimeType="application/font-woff2" />
             <mimeMap fileExtension="ttf" mimeType="application/font-ttf" />
             <mimeMap fileExtension="csv" mimeType="text/plain" />
      </staticContent>
     </system.webServer>
</configuration>

You can pick and choose the values you need for fileextensions.