Modern economists talking about "interest rates" are talking about the base interest rate which is the cost of bank borrowing which creates new money. Friedman was also interested in regulating the supply of new money but wanted to try to fix the quantity of a monetary aggregate, which could be achieved by.... tweaking base interest rates. The modern central banking approach is to fix the base interest rate (essentially the price of creating money) for a fixed period and be more cautious about adjusting it rather than try to directly fix the quantity of money. Central bankers tried Friedman's approach of fixing the quantity of [a particular aggregate of] money in the early 1980s, it was extremely unstable with wild interest rate lurches needed to fix the quantity of the monetary base (and the monetary aggregates the bank wasn't targeting still wildly fluctuated in volume) and even Friedman conceded that with hindsight he might have made different recommendations. So they switched to fixing the price of credit rather than the quantity instead
The modern policy is consistent with what both Friedman and central bankers wanted to achieve (a relatively low and predictable rate of inflation). They raise base rates because the economy is growing and the level of borrowing with it. But they're not interested in raising interest rates so rapidly that firms end up with the same low level of borrowing as before, merely in stopping credit expansions from growing too fast and creating price inflation (and conversely, making it cheaper and easier to borrow when lending drops) so the interest rate rises tend to track rather than halt the natural rise in lending.