How to add question sign on azeri keyboard layout?

mnamiz wrote:

You mean fn button Period button?

No, not fn. İt is Option Period. Hold the Option key ⌥ and then the last button on the right in the bottom row. What happens when you do that? I get "?"

mnamiz wrote:

When I open Keyboard User, its open like a dictionary. And on the list there is no Azeri language

I think you are in the wrong place. Follow this instruction from the Apple link:

choose Apple menu  > System Preferences, click Keyboard, click Keyboard, then select “Show keyboard and emoji viewers in menu bar.”

Then you go to the "flag" menu at the top right of the screen and select Show Keyboard Viewer".

Don't you have it at Option Period (where Period is the rightmost key on the bottom row)?

To find which key does what, use Keyboard Viewer

https://support.apple.com/guide/mac-help/use-the-keyboard-viewer-on-mac-mchlp1015/10.14/mac/10.14