>>Use the code given in the link:

 <system.webServer>
>>    <staticContent>
>>      <remove fileExtension=".woff" /> <!-- In case IIS already has this mime type -->
>>      <mimeMap fileExtension=".woff" mimeType="application/x-font-woff" />
>>    </staticContent>    
>>  </system.webServer>

>>
>
>That code was already in web config. I just need the same for extension woff2.

Then you just need to duplicate it and add some '2''s ?