How to setup hotkey for custom MEL Script?



I have write very simple MEL script and put it on a shelf as a icon. It works. Now I wish to set a hot key for it.
How to do it?
My hotkey editor says there is: No “Custom Scripts” have been saved yet.
While in fact I have saved it (maybe did sth wrong and maya does not recognise it from whatever reason).

I have searched youtube, but noone tackled exact thing i want to do.

This does not apply, there is nothing “new” to make, in maya 2018.

Neither this was helpful:

Thanks for help



I had to add script in runtime command editor tab.