Cannot install pyside6 from pip

I'm looking at the Qt for Python1 documentation on how to install PySide6 and it should be simple enough:

pip install pyside6

It doesn't work, though:

ERROR: Could not find a version that satisfies the requirement pyside6 (from versions: none)
ERROR: No matching distribution found for pyside6

I looked for it at pypi.org and found out the name of the package is PySide6, capitalized, not pyside6. Still, I tried it again, but had no luck:

$ sudo pip install PySide6
ERROR: Could not find a version that satisfies the requirement PySide6 (from versions: none)
ERROR: No matching distribution found for PySide6

Even if I explicitly pass --index-url to pip, as described in the official documentation, pip can't find pyside6 to install:

$ sudo pip install --index-url=https://download.qt.io/snapshots/ci/pyside/6.5/latest/ PySide6 --trusted-host download.qt.io
Looking in indexes: https://download.qt.io/snapshots/ci/pyside/6.0.0/latest
ERROR: Could not find a version that satisfies the requirement pyside6 (from versions: none)
ERROR: No matching distribution found for pyside6

(I tried several combinations of urls and package names)

Any idea to what's going on? Other pyside versions are available apparently. Not pyside6, though.

System information

$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 11 (bullseye)
Release:        11
Codename:       bullseye
$ python3 --version
Python 3.9.2
$ pip --version
pip 23.0.1 from /usr/local/lib/python3.9/dist-packages/pip (python 3.9)

The PySide6 project appears to be horribly inconsistent with the windows python versions they release for!

If you look through the version history for the package on PyPi, clicking on the "Download files" tab for each one you'll see what I'm referring to.

6.0.0: https://pypi.org/project/PySide6/6.0.0/#files
supports "regular" python 3.6-3.9 (cpython: cp36 cp37 cp38 cp39)

6.2.0: https://pypi.org/project/PySide6/6.2.0/#files
still good, regular cpython 3.6 - 3.10 (cp36 cp37 cp38 cp39 cp310)

6.3.2: https://pypi.org/project/PySide6/6.3.2/#files
cp36 only? Why?

6.4.0: https://pypi.org/project/PySide6/6.4.0/#files
cp36 and pp39. So "normal" python 3.6 (a deprecated version even then) and pypy 3.9 only.

6.4.0.1: https://pypi.org/project/PySide6/6.4.0.1/#files
cp37 and pp39. So they upgraded "normal" python to just 3.7 and the same pypy 3.9 only. 3.7 is reacing EOL in a month, so still very old.

And that's the way it's been ever since, publishing only for an almost obsolete python 3.7 and an alternate python pypy 3.9.

This is why when you try to just "pip install pyside6" on windows it will almost always fail, because there's no published support for the commonly installed python versions on windows.

Try to specify version:

pip install pyside6==6.0

Also in the link which you provided it is necessary to create folder:

> Creating and activating an environment You can do this by running the following on a terminal:
python -m venv env, (Your Python executable might be called python3)

> source env/bin/activate for Linux and macOS

> env\Scripts\activate.bat for Windows

In your question I do not see this step.