PowerBI Server Reverse Proxy

Hi, was able to setup my reverse proxy. Now IIS proxies the request to the outside URL to my local server on which I have installed PBI Reporting Service.

I produced the following steps:

* Inside the Default Website I have added a new Application with the same path like I have configured for the Web Portal URL

* I created a rewrite rule:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <rewrite>
            <rules>
                <clear />
                <rule name="ReverseProxyInboundRule1" enabled="true" stopProcessing="true">
                    <match url="(.*)" />
                    <conditions logicalGrouping="MatchAll" trackAllCaptures="false" />
                    <action type="Rewrite" url="http://localhost/Reports/{R:1}" appendQueryString="true" />
                </rule>
                <rule name="ReverseProxyInboundRule2" stopProcessing="true">
                    <match url="(.*)" />
                    <conditions logicalGrouping="MatchAll" trackAllCaptures="false">
                        <add input="{CACHE_URL}" pattern="^(https?)://" />
                    </conditions>
                    <action type="Rewrite" url="{C:1}://localhost/Reports/{R:1}" />
                </rule>
            </rules>
        </rewrite>
        <!-- <staticContent> -->
            <!-- <mimeMap fileExtension=".webmanifest" mimeType="application/manifest+json" /> -->
        <!-- </staticContent> -->
    </system.webServer>
</configuration>

(Replace localhost with whatever IP or URL of the server hosting the web portal).

Then, it kind of worked.... I was able to browse the Web Portal and click here and there... However, when trying to open a report I ran into another issue:

When opening a report a new request is made to www.url.de/powerbi/?queryblabla

When opening the same report locally it works, but the request shows this url: http://localhost/Reports/powerbi/?queryblabla

Apparently the rewritten URL is omitted at this stage and I am not fluent enough with IIS to also rewrite the URL to www.url.de/Reports/powerbi/?queryblabla

I am not sure whether or not this is the actual reason for the error. But I'd like to find out.