Is receiving money in exchange for displaying goods in a market rented out by the state, by the person who rented it, considered a form of "makas" (unlawful gain)? And what is the definition of "makas," with an example?

The maks (illegal tax/toll) is the unjust taking of people's money without compensation, and it is considered a major sin (kabira). It was mentioned in the hadith: "The master of maks will not enter Paradise." Although Al-Albani deemed it weak, scholars like Al-Munawi, Al-Dhahabi, and others considered it one of the greatest destructive sins. The master of maks resembles a highway robber; indeed, he may be more oppressive if he treats people harshly and imposes new taxes on them. The collector of the maks, its scribe, and its recipient are partners in sin and consume illicit gain (suht). However, if public interest necessitates that the state lease the market to an individual or individuals, that is permissible. The lessee then owns the usufruct of the market and is allowed to collect a sum from those who display their goods there, provided that he does not treat them unjustly. This is not considered maks.