Python : unable to connect to localhost using flask app

I'm a beginner in Flask and we run a simple web app at univeristy where you connect to a localhost and you get a simple Hello World text . However when I try to run the app after the flask app loads with the code below :

* Serving Flask app "my_app" (lazy loading)
* Environment: production
WARNING: This is a development server. Do not use it in a production deployment.
Use a production WSGI server instead.
* Debug mode: off
* Running on http://0.0.0.0:5000/ (Press CTRL+C to quit)

Then i press CTRL +C to quit and then I try to run my app to connect to the webpage using the command

curl localhost:5000/

and I get the error message :

curl : Prefix of  URI not recognised.
  At line:1 char:1
    + curl localhost:5000/
    + ~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotImplemented: (:) [Invoke-WebRequest], NotSupportedException
    + FullyQualifiedErrorId : 
    WebCmdletIEDomNotSupportedException,Microsoft.PowerShell.Commands.InvokeWebRequestCommand

I have tried changing the command to curl.exe localhost:500/ but the result is the same . I have my code below for the web app :

from flask import Flask
app = Flask(__name__)

 @app.route('/')
 def hello_world():
     return 'Hello World!'
 @app.route('/<name>')
 def hello_name(name):
     return f'Hello {name}!\n'

 if __name__ == '__main__':
       app.run(host='0.0.0.0')

I would appreciate your help with guiding me to run my app . Thank you in advance.

EDIT: the problem was simply that I would terminate my app without opening a shell to connect to the localhost . Thank you for your responses very much