Can't see featured image in articles

I installed Illidy theme and began to customize it.
I wrote an article but when I add a featured image it doesn’t appear, neither behind title nor on top of page.
Is there a way to display it?
Here the concerned page:
I would like to have the featured image displayed behind the top title (in place of yellow background) or at the top of the content, just before text.



Hi again,
I found how to display it, so you can forgive my topic… Thanks!

Hi, there

I will close this case now, Feel free to contact us again if you have other questions