What happens when you put the bill under your pillow? feng shui
According to geomantic omen, putting something under the pillow has little effect on geomantic omen, but some spells are related to it, but there is no mention of the bill.
Personally, I think it's better to put the bill in a drawer or somewhere else, because the bill represents payment and settlement, and it always feels bad.
Why don't you hang a treasure gourd on the bedside? It's sold online.