Following will redirect the root domain only, not the pages,
www.test.com > www.example.com - this will redirect
www.test.com/default.aspx > this will not redirect
<rewrite>
<rules>
<rule name="Root Redirect" enabled="true" stopProcessing="true">
<match url="^$" />
<action type="Redirect" url="https://www.example.com/" />
</rule>
</rules>
</rewrite>
