How to add robots.txt exception to web.config?

Question

robots.txt

there is a working rule for redirecting to https:
< rule name=" Redirect to https " stopProcessing=" true " >
< match url=".*" / >
< conditions>
< add input="{HTTPS}" pattern="off" ignoreCase="true" / >
< / conditions >
< action type="Redirect" url=" https://{HTTP_HOST}{REQUEST_URI} " redirectType="Permanent" appendQueryString="false" / >
< / rule >
how to add exception for robots.txt?
those. to be similar to this rule in .htaccess:
RewriteCond %{HTTP:X-HTTPS} !1
RewriteCond %{REQUEST_URI} !