Greetings @romnan,
Using the Debian package search: Debian -- Packages
I couldn’t find the python3-spidev package. Though there’s a python3 spidev package install-able via pip: spidev · PyPI
Perhaps is this what you’re looking for?
In order to have the extension install packages via pip rather than apt you want to instead list in in requirements.txt. As stated here: Python Development and Debugging on TorizonCore Using Visual Studio Code | Toradex Developer Center
Best Regards,
Jeremias