I tried to change the value of EditDriver's "prop" by adding "Add Driver" to the shape key. But I don't know how.

I can write code to AddDriver and "Add Input Variable" to the selected object.

import bpy

obj = bpy.context.active_object
obj_driver = obj.data.shape_keys.key_blocks['Key 1'].driver_add("value")
drvVar = obj_driver.driver.variables.new()

enter image description here

How can I change the value of prop and enter the data path?