The main function of this "fuel money" is to supply the monks in the temple and the ever-burning lamps in front of the Buddha. In fact, in ancient times, monks did not accept labor remuneration, that is, there was no source of income. Therefore, the daily expenses of the temple need the ideas of people who come to worship Buddha for peace. As for whether everyone has to pay the "fuel fee", there is actually no such provision.
Because there is no distinction between rich and poor before the Buddha, it all depends on one's economic situation and one's own kindness. After all, the Buddha is kind and tolerant, and it will not stop blessing just because a person has not donated "oil money".