Cli won't create venv for new project

╰─λ python3 -m mypy new
? What do you want to do? Flask
? What's your Project name? [my_project] plusin
error: externally-managed-environment

× This environment is externally managed
╰─> To install Python packages system-wide, try 'pacman -S
python-xyz', where xyz is the package you are trying to
install.

If you wish to install a non-Arch-packaged Python package,
create a virtual environment using 'python -m venv path/to/venv'.
Then use path/to/venv/bin/python and path/to/venv/bin/pip.

If you wish to install a non-Arch packaged Python application,
it may be easiest to use 'pipx install xyz', which will manage a
virtual environment for you. Make sure you have python-pipx
installed via pacman.

note: If you believe this is a mistake, please contact your Python installation or OS distribution provider. You can override this, at the risk of breaking your Python installation or OS, by passing --break-system-packages.
hint: See PEP 668 for the detailed specification.
sh: -c: line 9: syntax error near unexpected token debug=True' sh: -c: line 9: app.run(debug=True)' > app.py'
Project created.

Reproduce the reported flow with python3 -m mypy new, selecting Flask and the project name plusin. Start from the CLI entry point that handles project creation and inspect the commands used to create the virtual environment and write app.py. Done means the command creates the environment and Flask project without the externally managed environment or shell syntax errors.