Python flask on IIS deployment error - the requested URL was not found on the server

I am trying to deploy Python flask app in IIS

python Code
from flask import Flask
# Create a Flask application instance
app = Flask(__name__)
# Define a route and a corresponding function
@app.route('/')
def hello():
    return 'Hello, World!'
# Run the application if this script is executed directly
if __name__ == '__main__':
  app.run()`

`
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <handlers>
            <add name="SampleModulehandler" path="*" verb="*" modules="FastCgiModule" scriptProcessor="D:\WebApplications\SampleApp\samplevenv\Scripts\python.exe|D:\WebApplications\SampleApp\samplevenv\lib\site-packages\wfastcgi.py" resourceType="Unspecified" />
    </handlers>
    </system.webServer>
    <appSettings>
    <add key="WSGI_HANDLER" value="flaskiis.app" /> <!-- {name_of_file}.{name_of_flask_app}-->
    <add key="PYTHONPATH" value="D:\WebApplications\SampleApp" />
    </appSettings>
</configuration>`

`
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <handlers>
            <add name="SampleModulehandler" path="*" verb="*" modules="FastCgiModule" scriptProcessor="D:\WebApplications\SampleApp\samplevenv\Scripts\python.exe|D:\WebApplications\SampleApp\samplevenv\lib\site-packages\wfastcgi.py" resourceType="Unspecified" />
    </handlers>
    </system.webServer>
    <appSettings>
    <add key="WSGI_HANDLER" value="flaskiis.app" /> <!-- {name_of_file}.{name_of_flask_app}-->
    <add key="PYTHONPATH" value="D:\WebApplications\SampleApp" />
    </appSettings>
</configuration>`