Deploy multiple node.js applications into one web application fails - node.js

Question

I read that a deployment of many node.js applications in one azure web app is possible. So I wanted to try it. I created three node.js applications using express, and placed them as following:
TestApplication
-testapp0
node_modules
index.js
package.json
package-lock.json
web.config
-testapp1
node_modules
index.js
package.json
package-lock.json
web.config
-testapp2
node_modules
index.js
package.json
package-lock.json
web.config
Every index.js has almost the exact same code. The output is the only thing that changes.
In the web.config I changed the names of the handlers and rules.
index.js
const express = require("express");
const app = express();
app.get("/", (_, res)=>{
res.status(200).send("Welcome to TestApp0"); // testapp1: Welcome to TestApp1, testapp2: Welcome to TestApp2
});
app.get("/test", (_, res)=>{
res.status(200).send("TestApp0 TestPath"); //testapp1: TestApp1 TestPath, testapp2: TestApp2 TestPath
});
const PORT = process.env.PORT || 1337;
app.listen(PORT, () => console.log(`Listening to http://localhost:${PORT}`));
web.config
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<system.webServer>
<webSocket enabled="false" />
<handlers>
<!-- name="iisnode1" for testapp1 and name="iisnode2" for testapp -->
<add name="iisnode0" path="index.js" verb="*" modules="iisnode"/>
</handlers>
<rewrite>
<rules>
<!-- name="NodeInspector1" for testapp1 and name="NodeInspector2" for testapp -->
<rule name="NodeInspector0" patternSyntax="ECMAScript" stopProcessing="true">
<match url="^index.js\/debug[\/]?" />
</rule>
<!-- name="StaticContent1" for testapp1 and name="StaticContent2" for testapp -->
<rule name="StaticContent0">
<action type="Rewrite" url="public{REQUEST_URI}"/>
</rule>
<!-- name="DynamicContent1" for testapp1 and name="DynamicContent2" for testapp -->
<rule name="DynamicContent0">
<conditions>
<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="True"/>
</conditions>
<action type="Rewrite" url="index.js"/>
</rule>
</rules>
</rewrite>
<security>
<requestFiltering>
<hiddenSegments>
<remove segment="bin"/>
</hiddenSegments>
</requestFiltering>
</security>
<httpErrors existingResponse="PassThrough" />
</system.webServer>
</configuration>
Once I had the code ready, I deployed the File TestApplication to Azure using the Azure App Service extension in VSCode.
Before that I took care to change the Settings of "Path Mapping":
| virtueller Pfad | Physischer Pfad | Typ |
---------------------------------------------------------
| / | site\wwwroot\testapp0 | Application |
| /testapp1 | site\wwwroot\testapp1 | Application |
| /testapp2 | site\wwwroot\testapp2 | Application |
When I start the application I go, as desired, straight to testapp0 and when I enter the "/test" path, it shows me the desired output "TestApp0 TestPath".
I wanted to see in the screen the following:
"Welcome to TestApp0" when I go to "/" it works
"TestApp0 TestPath" when I go to "/test" it works
"Welcome to TestApp1" when I go to "/testapp1" instead I get "Cannot GET /testapp1"
"TestApp1 TestPath" when I go to "/testapp1/test" instead I get "Cannot GET /testapp1/test"
"Welcome to TestApp2" when I go to "/testapp2" instead I get "Cannot GET /testapp2"
"TestApp2 TestPath" when I go to "/testapp2/test" instead I get "Cannot GET /testapp2/test"
I tried to look everywhere for a way to achieve this. But sadly I haven't found a solution that worked and there is not much literature that I can read.
I assume that this isn't working because the node application (testapp0) looks for a path that is called "/testapp1" and there isn't any. That is why I get the "Cannot get" Error. But I want to switch to the other node application (testapp1) as soon as I enter "/testapp1" and then with "/testapp1/test" get the desired output. What am I doing wrong? I haven't found anything helpful and I am new to Azure. That is why guidance would be appreciated.
Thank you for your time!