I have two inputs in my circuit which I am feeding using the two jumper wires. I want to use a 3.5 mm female jack in place of those jumper wires. Right now I have this 3.5 mm female jack but i don't know how to wire it. I only need 3 pins i.e input1 , input2 and ground.
There is a diagram on the data sheet you linked to! 1 is the sleeve (usually ground), 3 is the tip (input 1) and 2 is the ring (input 2). 4 and 5 are a switch which is opened when a male jack is inserted. You can check using a male plug with 3 wires attached to tip, ring, and sleeve, and a multimeter.