You burn joss paper, not a real currency. Joss paper also known as incense paper is papercrafts or sheets of paper made into burnt offerings common in Chinese ancestral worship (such as the veneration of deceased family members and relatives on holidays and special occasions). Worship of deities in Chinese folk religion also uses a similar type of joss paper. Joss paper, as well as other papier-mâché items, are also burned or buried in various Asian funerals, “to ensure that the spirit of the deceased has sufficient needs in the afterlife.”
In other words, burn something that represents money. A picture of a bunch of cash or a check burning ritual will do. Please don’t burn your hard-earned money! That’s against the law in most places. Most Chinese or Asian stores in “Chinatown” neighborhoods will have it.