What you see is clickbait. It's perfectly legal to skip lunch and go home earlier or work remotely and so on.
> Until now, any company allowing employees to eat lunch at their desks was subject to a fine if discovered by the inspectors who enforce the labor code. The employee in question faced unspecified disciplinary action.[0]
The "until now" refers to the suspension of the law in 2021 to promote social distancing due to the COVID-19 pandemic. That suspension has since expired, so eating at one's desk is once again prohibited.
The actual law is Article R4228-19: "Il est interdit de laisser les travailleurs prendre leur repas dans les locaux affectés au travail."[1] Google translates this as "It is forbidden to allow workers to take their meals in the premises assigned to the work."
[0] https://www.nytimes.com/2021/02/07/world/europe/france-desk-...
[1] https://www.legifrance.gouv.fr/codes/article_lc/LEGIARTI0000...