Flask not running properly [duplicate]

Question

I am trying to get started on flask but have some teething issues...

In the terminal I am using the commands:

> set FLASK_APP=hello.py
> set FLASK_ENV=development
> flask run

After the first 2 commands there is no error message which I take as everything is fine but then when I try to run then it goes pair-shaped.

PS C:\Users\radoy\Programming> python -m flask --version
Python 3.9.12
Flask 2.1.1
Werkzeug 2.1.1
PS C:\Users\radoy\Programming> set FLASK_APP=hello.py   
PS C:\Users\radoy\Programming> set FLASK_ENV=development
PS C:\Users\radoy\Programming> flask run      
flask: The term 'flask' is not recognized as a name of a cmdlet, function, script file, or executable program.
Check the spelling of the name, or if a path was included, verify that the path is correct and try again.

What am I doing wrong ?