web.config

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <staticContent>
            <mimeMap fileExtension=".jsgz" mimeType="application/octet-stream" />
            <mimeMap fileExtension=".memgz" mimeType="application/octet-stream" />
            <mimeMap fileExtension=".datagz" mimeType="application/octet-stream" />
            <mimeMap fileExtension=".unity3dgz" mimeType="application/octet-stream" />
        </staticContent>
        <rewrite>
            <rules>
                <rule name="Append gz suffix to WebGL content requests">
                    <match url="(.*)\.(js|data|mem|unity3d)$" />
                    <conditions>
                        <add input="{HTTP_ACCEPT_ENCODING}" pattern="gzip" />
                        <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
                    </conditions>
                    <action type="Rewrite" url="{R:1}.{R:2}gz" />
                </rule>
            </rules>
            <outboundRules>
                <rule name="Append gzip Content-Encoding header to rewritten responses">
                    <match serverVariable="RESPONSE_Content-Encoding" pattern=".*" />
                    <conditions>
                        <add input="{REQUEST_FILENAME}" pattern="\.(js|data|mem|unity3d)gz$" />
                    </conditions>
                    <action type="Rewrite" value="gzip" />
                </rule>
            </outboundRules>
        </rewrite>
    </system.webServer>
</configuration>