Why can't I use CLI to start Flask applications?

Python version 3.6
Flask version 0.12.2
tried to run a development server using Flask-CLi, but it was unsuccessful anyway.

clipboard.png

can be started in the following ways:

if __name__ == "__main__":
    app.run()
Mar.05,2021

the environment variable FLASK_APP was not found.

I remember that set in Powershell just defines a variable, not an environment variable.

try $env:FLASK_APP = "dispatch.py"

The correct way to write

is set FLASK_APP=dispatch.py
"=" with no spaces on either side

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b3052f-2bcea.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b3052f-2bcea.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?