UI Button Raycast By Z Axis

Hello,
I'm trying to prepare an Interactive tutorial for my game's UI. I have made a GameObject with image component with 0 alpha to cover all screen to block UI elements from triggering during the tutorial.

And to make player able to click on target object, I changed target button's Z axis. (blockerElement's Z - 10, camera is at around z = -140)

The problem is, even though by Z axis of my target button is correctly appointed, it's still not clickable. I believe it's caused by the canvas game object hiearchy. Do you have any advice? I'm using new unity input system if it's important.

Example Hiearchy (I hope it will be understandable)

Canvas

-Panel Container

--Button Container

 ---Target Button  

-RayCastBlocker object