This is a simple way to make 1x4 keypad membrane to work

You Will need
1 - 1x4 Keypad Membrane

4 - 10k ohm resistor (any watts preferably 1/4)

Optional
jumper cables

Step 1: Connections

Here is the connection diagram.

Step 2: The Code

download the code then paste it to the arduino ide

you can see the output in the Arduino IDE Serial Monitor

Thanks!