I try to use the siunitx package in TeXstudio, as far as I know \si is the old version and \qty is the new version.
I tried following:
\documentclass{article}
\usepackage{siunitx}
\begin{document}
\qty[mode = text]{1.23}{J.mol^{-1}.K^{-1}} \\
\qty{.23e7}{\candela} \\
\qty[per-mode = symbol]{1.99}{\per\kilogram} \\
\qty[per-mode = fraction]{1,345}{\coulomb\per\mole}
\end{document}
The \qty is included in the auto completion, but the PDF is not created correctly.

I am using Ubuntu 20.04, I tried the code above in Overleaf and there it is working totally fine.
Can you help me find the problem?
Thanks in advance!
siunitx): add\listfilesto your input and report thesiunitxversion from theFile listin the.log. – Joseph Wright Mar 16 '22 at 16:53siunitxversion 2,\qtyis from version 3. Both v2 and v3 supports\SI{...}{...}though (in v3\SI = \qty– daleif Mar 16 '22 at 16:55apt/apt-getyou essentially have a frozen system that cannot be updated. In that case you may want to stick to the oldsiunitxv2 interface. You can, however, remove theaptTeX live and install a "vanilla" TeX live from TUG.org that can be updated (see https://tex.stackexchange.com/q/1092/35864) - but it still needs to be upgraded once a year (https://tex.stackexchange.com/q/107017/35864). – moewe Mar 21 '22 at 05:59