Money supply is charted as a vertical line in a supply curve. Demand is a downward sloping line. Where they intersect is where interest rates are. You can see from that supply curve how increasing money supply reduces interest rates. Why did interest rates reach near 20% in 1981? What was the central bank (Federal Reserve) trying to do to the economy? The money supply?
https://www.pbs.org/newshour/making-sense/what-led-to-the-high-interest/