Unable to update web.config to allow one url in iframe for Angular app hosted on Azure IIS

Question

I have an Angular 15 app hosted on Azure IIS that works correctly with a web.config file and I have X-Frame-Options set to "deny". However there is one path I would like to allow to be iFramed (as part of Azure authentication) but I am not able to modify the web.config to make it work. I can only either have everything "deny" or everything "allow".

Here is my web.config file where I have a rule on the main configuration that skips the rewrite if the url is "empty". Then I set up a location "empty" (i.e. https://myserver.com/empty) that is the same config with X-Frame-Options change to allow. However, I get 500 error "The page cannot be displayed because an internal server error has occurred".

If I remove the location and the rule with action="None" the empty page can be displayed with no error. Is there something I am missing?

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

  <system.webServer>
    <httpProtocol>
      <customHeaders>
        <add name="X-Frame-Options" value="deny" />
      </customHeaders>
    </httpProtocol>
    <staticContent>
      <mimeMap fileExtension=".json" mimeType="application/json" />
      <remove fileExtension=".woff" />
      <mimeMap fileExtension=".woff" mimeType="application/font-woff" />
      <mimeMap fileExtension=".woff2" mimeType="font/woff2" />
    </staticContent>
    <rewrite>
      <rules>
        <rule name="Empty Angular Route" stopProcessing="true">
          <match url="empty" />
          <action type="None" />
        </rule>
        <rule name="Angular Route" stopProcessing="true">
          <match url=".*" />
          <conditions logicalGrouping="MatchAll">
            <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
            <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
          </conditions>
          <action type="Rewrite" url="./index.html" />
        </rule>
      </rules>
    </rewrite>
  </system.webServer>

  <location path="empty">
    <system.webServer>
      <httpProtocol>
        <customHeaders>
          <remove name="X-Frame-Options"/>
        </customHeaders>
      </httpProtocol>
      <staticContent>
        <mimeMap fileExtension=".json" mimeType="application/json" />
        <remove fileExtension=".woff" />
        <mimeMap fileExtension=".woff" mimeType="application/font-woff" />
        <mimeMap fileExtension=".woff2" mimeType="font/woff2" />
      </staticContent>
      <rewrite>
        <rules>
          <rule name="Empty Angular Route" stopProcessing="true">
            <match url="empty" />
            <conditions logicalGrouping="MatchAll">
              <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
              <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
            </conditions>
            <action type="Rewrite" url="./index.html" />
          </rule>
        </rules>
      </rewrite>
    </system.webServer>
  </location>

</configuration>

Edit: Interestingly enough, I can get it to work with a static html page. Angular app is set to "deny" but the html page is set to "allow"

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <system.webServer>
    <httpProtocol>
      <customHeaders>
        <add name="X-Frame-Options" value="deny" />
      </customHeaders>
    </httpProtocol>
    <staticContent>
      <mimeMap fileExtension=".json" mimeType="application/json" />
      <remove fileExtension=".woff" />
      <mimeMap fileExtension=".woff" mimeType="application/font-woff" />
      <mimeMap fileExtension=".woff2" mimeType="font/woff2" />
    </staticContent>
    <rewrite>
      <rules>
        <rule name="Empty Page" stopProcessing="true">
          <match url="empty.html" />
          <action type="None" />
        </rule>
        <rule name="Angular Routes" stopProcessing="true">
          <match url=".*" />
          <conditions logicalGrouping="MatchAll">
            <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
            <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
          </conditions>
          <action type="Rewrite" url="./index.html" />
        </rule>
      </rules>
    </rewrite>
  </system.webServer>

  <location path="empty.html">
    <system.webServer>
      <httpProtocol>
        <customHeaders>
          <remove name="X-Frame-Options" />
        </customHeaders>
      </httpProtocol>
    </system.webServer>
  </location>

</configuration>