LyX is not finding packages

You need to make sure the TeXLive packages are at the top of the path list.

Go to Tools -> Preferences -> Paths
Next to PATH prefix, try putting in:
/usr/ias/texlive/20XX/bin/x86_64-linux (where 20XX is the TeXLive version that you want to load, e.g. 2023)

Click on Apply
Click on OK

To verify that the correct path is being used, go to 

Tools -> TeX Information, click on the box "Show path"

You may need to hit Rescan.