web.config rewrite all requests to index.html

web.config

<configuration>
    <system.webServer>
        <rewrite>
        <rules>
            <rule name="redirect all requests" stopProcessing="true">
                <match url="^(.*)$" ignoreCase="false" />
                <conditions logicalGrouping="MatchAll">
                    <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" pattern="" ignoreCase="false" />
                </conditions>
                <action type="Rewrite" url="index.html" appendQueryString="true" />
            </rule>
        </rules>
    </rewrite>
    </system.webServer>
</configuration>

Hi, I'm really not a dev. needed this code in my website for a temporary redirection.

What should I put as "REQUEST_FILENAME}" Should I put Index.html(It's where I want the redirection to go) or should I put all the other .html that I dont want accessible? thanks!

You don't need to change that, REQUEST_FILENAME is just a variable that represents whatever file has been requested. It will match requests to all other pages and make them inaccessible.