A trouble with VS Code

[Truman]

from flask import Flask

app = Flask(__name__)

@app.route('/')
def hello_world():
    return "Hello, World!"

form VS Code terminal I'm trying to give this command:
export FLASK_APP = minimal.py
but I get:

Error:
export : The term 'export' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, 
verify that the path is correct and try again.
At line:1 char:1
+ export FLASK_APP = minimal.py
+ ~~~~~~
    + CategoryInfo          : ObjectNotFound: (export:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

What am I doing wrong? Maybe this is for mac and should use windows command?

I tried with set FLASK_APP=minimal.py but:

Error:
Set-Variable : A positional parameter cannot be found that accepts argument 'minimal.py'.
At line:1 char:1
+ set FLASK_APP = minimal.py
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) [Set-Variable], ParameterBindingException
    + FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.PowerShell.Commands.SetVariableCommand