There is a chip is KF33, three-terminal voltage regulator IC, no need to connect any peripheral circuit, the first pin is connected to 5v input, the second pin is grounded, and the third pin is 3.3 volts output.
There is also a chip, called 1117-3.3, the same as KF33, is also an SMD package, that is, the package is slightly smaller, the connection is the same, the output voltage is also 3.3 volts to the general circuit, the voltage regulation requirements are no problem, the current is within the range of 1A.