Assign value to Input field

Hi all,

I am working with latest version of unity and have problems with assigning value to an Input filed from script. I made a custom inspector window. There I have one textbox. A made UI Input field in scene as well. My goal is that if I something write into textbox in the custom inspector window I'd like to see that text in Input field in the scene.

In inspector window I have something like:
Assign value to Input field