You can read all the other comments which explained why it is not open source. You can't really retrain the model without petabytes of data. Even if you "train" stuff on your dataset: it's more like tweaking the model weights a bit, rather than building the model from scratch.
"Open source" is PR talk by Meta and deepseek.
Mir hat mal wer die Kurzfassung von Das Kapital von Otto Rühle empfohlen. Und ich hab gutes gehört von "Das ABC des Kapitalismus".
Ich selber hab mir den Kram nur über Youtubevideos reingepfiffen. XD