OverSamplingOscillators not installed

Hello,

I built OverSamplingOscillators by Sam Pluta on a Linux machine (Ubuntu studio 22.04 / SuperCollider 3.13).
I used these command lines:

git clone https://github.com/spluta/OversamplingOscillators.git
cd OversamplingOscillators
mkdir build
cd build
cmake .. -DCMAKE_BUILD_TYPE=Release -DSC_PATH=<PATH TO SC SOURCE>
cmake --build . --config Release

Building looks ok, I went to 100% without errors but when I try to use them, I got this error:
exception in GraphDef_Load: UGen 'SinOscOS' not installed.
I assumed that some files are missing in the directory “OversamplingOscillators” (the one I moved to the Extensions folder).
In there, I can find 3 folder:
Classes, HelpSource and scx_files.

scx_files is empty, in Classes I have a file named OversamplingOscillators.sc and in HelpSource I have a bunch of schelp files.
Can someone help me to understand what I did wrong ?

I managed to make it work by moving all the .so that I found in the build directory to the OverSamplingOscillators folder in Extensions.
That’s weird