Images showing above blog posts

I have been unable to find the way to change the image above each blog post.
I am able to include images within the post text, but not on top!
Will you please point me in the right direction.

Hello there,

I hope you are doing well today.

You would have to add a featured image of the post to have the image appear on the top section. In order to add the featured image you need to edit the post then upload a featured image.

Best Regards,