How to leave the Friendly URL in Classic ASP?

I can only access the file by putting its extension, for example clients.php. I configured the web.config file this way, but I did not get results:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <rewrite>

            <rules>
                <rule name="home" stopProcessing="true">

                    <match url="^index/?([a-zA-Z0-9_-]+)?(.php)?$" />

                    <action type="Rewrite" url="/index.php" />

                </rule>


                <rule name="clientes" stopProcessing="true">

                    <match url="^clientes/([a-zA-Z0-9_-]+)?(.php)?$" />

                    <action type="Rewrite" url="/clientes.php" />

                </rule>


                <rule name="sobre" stopProcessing="true">

                    <match url="^sobre-nos/?([a-zA-Z0-9_-]+)?(.html)?$" />

                    <action type="Rewrite" url="/empresa.asp" />

                </rule>


            </rules>

        </rewrite>

    </system.webServer>
</configuration>