Hi,
I am installing my new Wyze doorbell. I just want to make sure what to bypass in my mechanical chime box. See pic attached. I have one old doorbell switch in the front door.
Welcome to the community @Marouane
let me first state that I am not an electrician, but have assisted my colleague in hooking his up and installed my v1 Doorbell.
Based on the image you provided, it looks like you would Jumper the 2 wires screwed into the Chime.
However, the terminals are numbered 1, 2, 3., do you have documentation as to what each of those are? Can you also provide the type of chime you have so we can be sure?
I dont have any documentation about the chime I have. There are 2 black wires screwed on 2, and one white wire screwed on 3.
Yea. Saw that bis there a model number on it somewhere you can see?
I think jumpering those two screws will do it for you though.
Edit
I think the 2 black wires go to 2 separate doors. The white may go to a transformer. One of those black wires probably should have been on the free screw.
Should be low voltage, you could check that with an ohm meter.
Do you have a voltage meter or a way to measure the voltage between a few of those wires? that would be a way to tell if those are the correct wires. Do you know where the transformer is? what is its power rating?
I am not a doorbell chime expert but ive never seen a chime with a battery backup. 
