The most reliable way to get the library is through the built-in tools in the Arduino IDE. Method 1: Arduino Library Manager (Recommended)
For developers and hobbyists working with matrix keypads, the library is the standard solution for handling user input on Arduino and other microcontrollers. This library simplifies the complex task of scanning rows and columns to detect keypresses, handling debouncing automatically. How to Download and Install Keypad.h biblioteca keypad.h download
This is the fastest method and ensures you always have the latest version compatible with your IDE. Open the Arduino IDE. The most reliable way to get the library